biosights

Lymphatic exosomes help dendritic cells find their way Under inflammatory conditions, antigen-presenting dendritic cells are attracted to lymphatic vessels by chemokines secreted from the basolateral surface of lymphatic endothelial cells. Brown et al. reveal that lymphatic endothelial cells also release exosomal vesicles that, by inducing the formation of cellular protrusions, improve the ability of dendritic cells to detect guidance cues and navigate their way through complex tissue environments. This biosights episode presents the paper by Brown et al. from the June 4th, 2018, issue of the Journal of Cell Biology and includes an interview with one of the paper's senior authors, Dontscho Kerjaschki (Medical University of Vienna). Produced by Caitlin Sedwick and Ben Short. See the associated paper in JCB for details on the funding provided to support this original research. Subscribe to biosights via iTunes or RSS View biosights archive The Rockefeller University Press biosights@rockefeller.edu

BBSome trains provide receptors a passage out of cilia Many G protein–coupled receptors accumulate in the membrane of primary cilia and then exit this sensory organelle when their signaling pathway is activated. Ye et al. reveal that the BBSome complex facilitates the signal-dependent exit of GPCRs by moving them across a diffusion barrier located at the ciliary transition zone, although the receptors must then cross a second, periciliary diffusion barrier to completely exit the cilium. This biosights episode presents the paper by Ye et al. from the May 7th, 2018, issue of the Journal of Cell Biology and includes an interview with the paper's senior author, Maxence Nachury (University of California, San Francisco). Produced by Caitlin Sedwick and Ben Short. See the associated paper in JCB for details on the funding provided to support this original research. Subscribe to biosights via iTunes or RSS View biosights archive The Rockefeller University Press biosights@rockefeller.edu

Dia1-dependent adhesions help epithelia branch out The actin cytoskeleton and its regulators play key roles in the maturation and stabilization of focal adhesions but how adhesion maturation affects tissue morphogenesis is largely unknown. Fessenden et al. reveal that the actin-nucleating formin protein Dia1 promotes branching morphogenesis by stabilizing adhesions that are required for epithelial tissues to initiate invasion. This biosights episode presents the paper by Fessenden et al. from the April 2nd, 2018, issue of the Journal of Cell Biology and includes an interview with the paper's senior author, Margaret Gardel (University of Chicago). Produced by Caitlin Sedwick and Ben Short. See the associated paper in JCB for details on the funding provided to support this original research. Subscribe to biosights via iTunes or RSS View biosights archive The Rockefeller University Press biosights@rockefeller.edu

The nucleus comes through in the clutch In addition to its roles in DNA replication and gene expression, the nucleus has an important physical impact on cellular behavior. Graham et al. reveal that, although the nucleus is dispensable for cell polarization and migration on 2D surfaces, it is crucial for regulating the cell's responses to mechanical cues. This biosights episode presents the paper by Graham et al. from the March 5th, 2018, issue of the Journal of Cell Biology and includes an interview with the paper's first author, David Graham, and its two senior authors, Jim Bear and Keith Burridge (University of North Carolina at Chapel Hill). Produced by Caitlin Sedwick and Ben Short. See the associated paper in JCB for details on the funding provided to support this original research. Subscribe to biosights via iTunes or RSS View biosights archive The Rockefeller University Press biosights@rockefeller.edu

Cytotoxic T cells use Flower power In order to efficiently kill multiple target cells, cytotoxic T lymphocytes must endocytose and recycle cytotoxic granule membrane components from the immunological synapse. Chang et al. reveal that a protein called Flower facilitates granule endocytosis in a calcium-dependent manner. This biosights episode presents the paper by Chang et al. from the February 5th, 2018, issue of the Journal of Cell Biology and includes an interview with one of the paper's senior authors, Jens Rettig (Saarland University, Saarbrücken, Germany). Produced by Caitlin Sedwick and Ben Short. See the associated paper in JCB for details on the funding provided to support this original research. Subscribe to biosights via iTunes or RSS View biosights archive The Rockefeller University Press biosights@rockefeller.edu

Ring out your dead: MRCKα cleavage triggers epithelial extrusion Dying epithelial cells are extruded from the tissue by a basal actomyosin ring formed in neighboring, healthy cells. Gagliardi et al. reveal that epithelial extrusion is also driven by actin rearrangements in the apoptotic cell, where cleavage of the kinase MRCKα induces the assembly of an apical actin ring that collapses the cell body and moves the dying cell upward. This biosights episode presents the paper by Gagliardi et al. from the January 2nd, 2018, issue of the Journal of Cell Biology and includes an interview with the paper's first author, Paolo Gagliardi (Candiolo Cancer Institute, Candiolo, Italy). Produced by Caitlin Sedwick and Ben Short. See the associated paper in JCB for details on the funding provided to support this original research. Subscribe to biosights via iTunes or RSS View biosights archive The Rockefeller University Press biosights@rockefeller.edu

Adult neuroblasts DOCK into position In the postnatal/adult brain, interneuron precursors, or neuroblasts, migrate along the rostral migratory stream by undergoing cycles of leading process extension followed by somal translocation. Nakamuta et al. reveal that the Rac/Cdc42 guanine nucleotide exchange factor DOCK7 coordinates this migratory cycle by regulating both Rac-dependent leading process extension and p116Rip-dependent actin assembly at the cell rear. This biosights episode presents the paper by Nakamuta et al. from the December 4th, 2017, issue of The Journal of Cell Biology and includes an interview with the paper's senior author, Linda Van Aelst (Cold Spring Harbor Laboratory, NY). Produced by Caitlin Sedwick and Ben Short. See the associated paper in JCB for details on the funding provided to support this original research. Subscribe to biosights via iTunes or RSS View biosights archive The Rockefeller University Press biosights@rockefeller.edu

Cancer-associated fibroblasts lay the tracks for directional migration Cancer-associated fibroblasts, or CAFs, regulate tumor progression by secreting chemokines and remodeling the extracellular matrix. Erdogan et al. reveal that the CAF-dependent alignment of fibronectin promotes directional cancer cell migration. This biosights episode presents the paper by Erdogan et al. from the November 6th, 2017, issue of The Journal of Cell Biology and includes an interview with two of the paper's authors, Begum Erdogan and Mingfang Ao (Vanderbilt University, Nashville, TN). Produced by Caitlin Sedwick and Ben Short. See the associated paper in JCB for details on the funding provided to support this original research. Subscribe to biosights via iTunes or RSS View biosights archive The Rockefeller University Press biosights@rockefeller.edu

Drp1 cuts off mitophagy Misfolded mitochondrial proteins can be eliminated by Parkin-dependent mitophagy but how this process selectively removes damaged mitochondrial regions is unclear. Burman et al. reveal that protein aggregates in the mitochondrial matrix trigger a local accumulation of Parkin on the mitochondrial outer membrane, and that the mitochondrial fission protein Drp1 segregates these domains to prevent Parkin accumulation from spreading and directing the elimination of healthy regions of the organelle. This biosights episode presents the paper by Burman et al. from the October 2nd, 2017, issue of The Journal of Cell Biology and includes an interview with the paper's senior author, Richard Youle (NINDS, NIH). Produced by Caitlin Sedwick and Ben Short. See the associated paper in JCB for details on the funding provided to support this original research.

Synaptic activity shifts dendritic lysosomes Invading pathogens or other toxic agents can trigger the assembly of the inflammasome adaptor ASC into large, intracellular specks that activate caspase-1 to initiate a proinflammatory cell death called pyroptosis. Kuri et al. follow the dynamics of ASC speck formation in live zebrafish, revealing their lethal effects on epidermal keratinocytes and their subsequent engulfment and degradation by macrophages. This biosights episode presents the paper by Kuri et al. from the September 4th, 2017, issue of The Journal of Cell Biology and includes an interview with two of the paper's authors, Paola Kuri and Maria Leptin (EMBL). Produced by Caitlin Sedwick and Ben Short. See the associated paper in JCB for details on the funding provided to support this original research.

Synaptic activity shifts dendritic lysosomes Lysosomes are known to exist in both the cell body and axon of neurons, but whether they also localize to dendrites is unclear. Goo et al. reveal that lysosomes do exist in dendrites and dendritic spines, and that their trafficking in this region of neurons is regulated by synaptic activity. This biosights episode presents the paper by Goo et al. from the August 7th, 2017, issue of The Journal of Cell Biology and includes an interview with the paper's senior author, Gentry Patrick (University of California, San Diego). Produced by Caitlin Sedwick and Ben Short. See the associated paper in JCB for details on the funding provided to support this original research. Subscribe to biosights via iTunes or RSS View biosights archive The Rockefeller University Press biosights@rockefeller.edu

Myosins team up to help secretory granules integrate Actomyosin contractility drives a variety of membrane remodeling events, including the integration of secretory granules into the apical plasma membrane after exocytosis. By visualizing granule integration in the salivary glands of live mice, Milberg et al. reveal that myosin IIA and myosin IIB act at different stages of the process and that the activation and assembly of these myosin isoforms into contractile filaments is regulated by the F-actin scaffold, which assembles on secretory granules and recruits myosin light chain kinase. This biosights episode presents the paper by Milberg et al. from the July 3rd, 2017, issue of The Journal of Cell Biology and includes an interview with the paper's senior author, Roberto Weigert (National Institutes of Health, Bethesda, MD). Produced by Caitlin Sedwick and Ben Short. See the associated paper in JCB for details on the funding provided to support this original research. Subscribe to biosights via iTunes or RSS View biosights archive The Rockefeller University Press biosights@rockefeller.edu

Broken chromosomes stay on the safe side in mitosis Unrepaired DNA double strand breaks can generate chromosome fragments that lack centromeres but, surprisingly, these acentric chromosomes can nevertheless segregate to spindle poles during mitosis. Karg et al. reveal that, in Drosophila melanogaster neuroblasts, acentric chromosomes segregate along interpolar microtubules at the spindle periphery that are organized by the chromokinesin motor protein Klp3a. This biosights episode presents the paper by Karg et al. from the June 5th, 2017, issue of The Journal of Cell Biology and includes an interview with the paper's senior author, William Sullivan (University of California, Santa Cruz). Produced by Caitlin Sedwick and Ben Short. See the associated paper in JCB for details on the funding provided to support this original research. Subscribe to biosights via iTunes or RSS View biosights archive The Rockefeller University Press biosights@rockefeller.edu

The cell cortex makes use of plastin's connections Cortical actomyosin contractility regulates a variety of morphogenetic processes at both the cellular and tissue-based levels. Ding et al. reveal that, in the Caenorhabditis elegans zygote, the actin cross-linking protein plastin optimizes connectivity within the cortical actomyosin network to coordinate large-scale contractile processes that drive cell polarization and cytokinesis. This biosights episode presents the paper by Ding et al. from the May 1st, 2017, issue of The Journal of Cell Biology and includes an interview with the paper's senior author, Ronen Zaidel-Bar (National University of Singapore). Produced by Caitlin Sedwick and Ben Short. See the associated paper in JCB for details on the funding provided to support this original research. Subscribe to biosights via iTunes or RSS View biosights archive The Rockefeller University Press biosights@rockefeller.edu

How Chlamydia help mitochondria keep it together The obligate intracellular bacterium Chlamydia trachomatis must keep its host cell alive, even though it produces reactive oxygen species that expose the host cell to oxidative stress. Chowdhury et al. reveal that Chlamydia mitigates this oxidative stress by down-regulating the mitochondrial fission protein DRP1 via a microRNA- and p53-dependent pathway, thereby maintaining the mitochondrial network and ATP production to promote host cell survival and bacterial growth. This biosights episode presents the paper by Chowdhury et al. from the April 3rd, 2017, issue of The Journal of Cell Biology and includes an interview with two of the paper's authors, Suvagata Roy Chowdhury and Thomas Rudel (University of Würzburg, Würzburg, Germany). Produced by Caitlin Sedwick and Ben Short. See the associated paper in JCB for details on the funding provided to support this original research. Subscribe to biosights via iTunes or RSS View biosights archive The Rockefeller University Press biosights@rockefeller.edu

Actin isoforms divide their responsibilities in motoneurons Actin dynamics are crucial for axon growth and branching, but most studies have only focused on the role of β-actin. Moradi et al. reveal that α-, β-, and γ-actin have different functions in motoneuron axons; locally translated α-actin forms stable actin filaments that promote the formation of axonal branches, whereas β-actin regulates growth cone dynamics. This biosights episode presents the paper by Moradi et al. from the March 6th, 2017, issue of The Journal of Cell Biology and includes an interview with the paper's senior author, Michael Sendtner (University Hospital Würzburg, Würzburg, Germany). Produced by Caitlin Sedwick and Ben Short. See the associated paper in JCB for details on the funding provided to support this original research. Subscribe to biosights via iTunes or RSS View biosights archive The Rockefeller University Press biosights@rockefeller.edu

Localizing mTORC2 activity The mTORC2 complex regulates cell growth and proliferation by phosphorylating the protein kinase Akt, but where in the cell mTORC2 is active, and how growth factors direct its activity towards Akt, remains unclear. Ebner et al. use a novel reporter to show that endogenous mTORC2 activity localizes to plasma membrane, mitochondrial, and endosomal pools with distinct sensitivities to PI3 kinase and growth factor signaling, and that growth factors induce Akt phosphorylation by promoting Akt's recruitment to the plasma membrane. This biosights episode presents the paper by Ebner et al. from the February 6th, 2017, issue of The Journal of Cell Biology and includes an interview with two of the paper's authors, Michael Ebner and Ivan Yudushkin (Max F. Perutz Laboratories and Medical University of Vienna, Vienna, Austria). Produced by Caitlin Sedwick and Ben Short. See the associated paper in JCB for details on the funding provided to support this original research. Subscribe to biosights via iTunes or RSS View biosights archive The Rockefeller University Press biosights@rockefeller.edu

Tumor cells feel the pressure after protease inhibition Primary fibroblasts use a high pressure, “nuclear piston” mode of migration to move through highly cross-linked 3D extracellular matrices. Petrie et al. reveal that tumor cells with high levels of matrix metalloproteinase activity generally migrate by forming lamellipodia but, when their protease activity is inhibited, they can switch to the nuclear piston mechanism to force their nuclei through small gaps in the extracellular matrix. This biosights episode presents the paper by Petrie et al. from the January 2nd, 2017, issue of The Journal of Cell Biology and includes an interview with the paper's senior author, Ryan Petrie (Drexel University, Philadelphia, PA). Produced by Caitlin Sedwick and Ben Short. See the associated paper in JCB for details on the funding provided to support this original research. Subscribe to biosights via iTunes or RSS View biosights archive The Rockefeller University Press biosights@rockefeller.edu

How NK cells avoid collateral damage Before secreting their lytic granules to kill transformed or virally infected cells, natural killer cells converge these lysosome-related organelles around the microtubule-organizing center. Hsu et al. reveal that, by promoting the granules' directed secretion at the immunological synapse, convergence both enhances the efficiency of target cell killing and limits the death of healthy bystander cells. This biosights episode presents the paper by Hsu et al. from the December 19th, 2016, issue of The Journal of Cell Biology and includes an interview with the paper's senior author, Jordan Orange (Baylor College of Medicine, Houston, TX). Produced by Caitlin Sedwick and Ben Short. See the associated paper in JCB for details on the funding provided to support this original research. Subscribe to biosights via iTunes or RSS View biosights archive The Rockefeller University Press biosights@rockefeller.edu

Formin' arcs at the immunological synapse When a T cell encounters an antigen-presenting cell, it dramatically reorganizes its cytoskeleton to form a specialized contact site called the immunological synapse. Murugesan et al. use superresolution microscopy to reveal that the medial region of the synapse contains a contractile network of formin-generated actomyosin arcs that sweep T cell receptor microclusters toward the center of the synapse. This biosights episode presents the paper by Murugesan et al. from the November 7th, 2016, issue of The Journal of Cell Biology and includes an interview with the paper's senior author, John Hammer (NHLBI, Bethesda, MD). Produced by Caitlin Sedwick and Ben Short. See the associated paper in JCB for details on the funding provided to support this original research.

Retinal ganglion cells have a backup plan Retinal ganglion cells (RGCs) are born at the apical side of the retinal neuroepithelium before they translocate to the basal side and send out axons to form the optic nerve. Icha et al. reveal that, in the zebrafish retina, RGC translocation is expedited by basal process attachment and a population of stable microtubules. If necessary, however, RGCs can switch to a backup, multipolar migratory mode to ensure that they reach the basal lamina in time to support the later stages of retinal development. This biosights episode presents the paper by Icha et al. from the October 24th, 2016, issue of The Journal of Cell Biology and includes an interview with the paper's senior author, Caren Norden (Max Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany). Produced by Caitlin Sedwick and Ben Short. See the associated paper in JCB for details on the funding provided to support this original research.  Subscribe to biosights via iTunes or RSS View biosights archive The Rockefeller University Press biosights@rockefeller.edu  

An iron hand controls endosome-mitochondria contacts In erythroid cells, endocytosed iron is directly transferred into mitochondria at dynamic endosome-mitochondria contacts. Das et al. reveal that this process also occurs in epithelial cells, and that the motility of endosomes, and the duration of their interactions with mitochondria, is modulated by intra-endosomal iron release from transferrin. This biosights episode presents the paper by Das et al. from the September 26th, 2016, issue of The Journal of Cell Biology and includes an interview with the paper's senior author, Margarida Barroso (Albany Medical College, Albany, NY). Produced by Caitlin Sedwick and Ben Short. See the associated paper in JCB for details on the funding provided to support this original research. Subscribe to biosights via iTunes or RSS View biosights archive The Rockefeller University Press biosights@rockefeller.edu

Septins step in to promote macropinosome fusion After they are formed by the closure of membrane ruffles, macropinosomes mature by fusing with each other and with endosomes, before eventually delivering their fluid phase cargo to lysosomes. Dolat and Spiliotis reveal that septin filaments promote macropinosome maturation and lysosomal delivery by facilitating macropinosome/endosome fusion. This biosights episode presents the paper by Dolat and Spiliotis from the August 29th, 2016, issue of The Journal of Cell Biology and includes an interview with the paper's senior author, Elias Spiliotis (Drexel University, Philadelphia, PA). Produced by Caitlin Sedwick and Ben Short. See the associated paper in JCB for details on the funding provided to support this original research. Subscribe to biosights via iTunes or RSS View biosights archive The Rockefeller University Press biosights@rockefeller.edu

The midbody enables ciliogenesis Fibroblasts initiate ciliogenesis inside the cell, but polarized epithelial cells form a primary cilium at the apical cell surface through a mechanism that is largely uncharacterized. Bernabé-Rubio et al. reveal that, in polarized MDCK cells, a remnant of the cytokinetic midbody moves to the center of the apical surface, where it encounters the centrosome and enables cilium formation. This biosights episode presents the paper by Bernabé-Rubio et al. from the August 1, 2016, issue of The Journal of Cell Biology and includes an interview with the paper's senior author, Miguel Alonso (Universidad Autónoma de Madrid, Spain). Produced by Caitlin Sedwick and Ben Short. See the associated paper in JCB for details on the funding provided to support this original research. Subscribe to biosights via iTunes or RSS View biosights archive The Rockefeller University Press biosights@rockefeller.edu

Mobilizing mitochondria aids axon regeneration In mature neurons, the axonal transport of mitochondria is suppressed by the expression of the mitochondrial anchoring protein syntaphilin. Zhou et al. reveal that enhancing mitochondrial transport in mature neurons rescues energy deficits and facilitates axon regeneration after injury. This biosights episode presents the paper by Zhou et al. from the July 4th, 2016, issue of The Journal of Cell Biology and includes an interview with the paper's senior author, Zu-Hang Sheng (National Institute of Neurological Disorders and Stroke, Bethesda, MD). Produced by Caitlin Sedwick and Ben Short. See the associated paper in JCB for details on the funding provided to support this original research. Subscribe to biosights via iTunes or RSS View biosights archive The Rockefeller University Press biosights@rockefeller.edu

Neural crest cells stay within versican's confines Spatial confinement enhances collective cell migration in vitro, but whether it promotes collective migration in vivo is unclear. Szabó et al. reveal that the extracellular matrix protein versican confines neural crest cells to enhance their collective migration during Xenopus laevis embryogenesis. This biosights episode presents the paper by Szabó et al. from the June 6th, 2016, issue of The Journal of Cell Biology and includes an interview with the paper's senior author, Roberto Mayor (University College London, London, England, UK). Produced by Caitlin Sedwick and Ben Short. See the associated paper in JCB for details on the funding provided to support this original research. Subscribe to biosights via iTunes or RSS View biosights archive The Rockefeller University Press biosights@rockefeller.edu

Surf's uptake! Exosomes ride filopodia into cells Exosomes are small, extracellular vesicles that transfer lipid, protein, and RNA cargoes between cells, but relatively little is known about how they are taken up and processed by their target cells. Heusermann et al. reveal that exosomes "surf" along recipient cell filopodia before being efficiently endocytosed and targeted to the endoplasmic reticulum. This biosights episode presents the paper by Heusermann et al. from the April 25, 2016, issue of The Journal of Cell Biology and includes an interview with the paper's senior author, Nicole Meisner-Kober (Novartis Institutes for Biomedical Research, Basel, Switzerland). Produced by Caitlin Sedwick and Ben Short. See the associated paper in JCB for details on the funding provided to support this original research. Subscribe to biosights via iTunes or RSS View biosights archive The Rockefeller University Press biosights@rockefeller.edu

Sac1 works its contacts The plasma membrane phosphoinositide PI(4,5)P2 is derived from PI(4)P, whose levels are controlled by the essential lipid phosphatase Sac1. Sac1 is an integral ER membrane protein, but Dickson et al. reveal that it localizes to dynamic ER–plasma membrane contact sites to regulate plasma membrane PI(4)P and PI(4,5)P2 levels. This biosights episode presents the paper by Dickson et al. from the April 11th, 2016, issue of The Journal of Cell Biology and includes an interview with the paper's corresponding author, Eamonn Dickson (University of Washington School of Medicine, Seattle, WA). Produced by Caitlin Sedwick and Ben Short. See the associated paper in JCB for details on the funding provided to support this original research. Subscribe to biosights via iTunes or RSS View biosights archive The Rockefeller University Press biosights@rockefeller.edu

Fat2 whips fly eggs into shape During Drosophila oogenesis, the collective migration of egg chamber follicle cells drives the chambers' rotation and elongation. Squarr et al. reveal that the atypical cadherin Fat2 recruits the WAVE regulatory complex to tricellular junctions to induce the formation of whip-like actin protrusions that control collective migration and tissue rotation. This biosights episode presents the paper by Squarr et al. from the February 29th, 2016, issue of The Journal of Cell Biology and includes an interview with the paper's senior author, Sven Bogdan (University of Münster, Münster, Germany). Produced by Caitlin Sedwick and Ben Short. See the associated paper in JCB for details on the funding provided to support this original research. Subscribe to biosights via iTunes or RSS View biosights archive The Rockefeller University Press biosights@rockefeller.edu

Chipping away at the problems of cardiac stem cell therapy Though stem cells transplanted into heart attack patients can develop into cardiomyocytes and integrate with undamaged host tissue, preclinical studies and clinical trials have only shown limited improvements in cardiac function. Using a simplified, in vitro, "muscle on-a-chip" system, Aratyn-Schaus et al. reveal that mechanical forces aren't transmitted efficiently between weaker, stem cell–derived cardiomyocytes and stronger, more mature host cells. This biosights episode presents the paper by Aratyn-Schaus et al. from the February 15th, 2016, issue of The Journal of Cell Biology and includes an interview with one of the paper's co-first authors, Francesco Pasqualini (Harvard University, Cambridge, MA). Produced by Caitlin Sedwick and Ben Short. See the associated paper in JCB for details on the funding provided to support this original research. Subscribe to biosights via iTunes or RSS View biosights archive The Rockefeller University Press biosights@rockefeller.edu

P-cadherin provides the driving force for collective cell migration Collective cell migration is an important process in normal development, wound repair, and tumor metastasis. Plutoni et al. reveal that the cell adhesion molecule P-cadherin promotes collective cell migration via the small GTPase Cdc42, inducing cell polarization and increasing the strength and orientation of mechanical forces. This biosights episode presents the paper by Plutoni et al. from the January 18th, 2016, issue of The Journal of Cell Biology and includes an interview with the paper's senior author, Cécile Gauthier-Rouvière (Centre de Recherche de Biochimie Macromoléculaire, Centre National de la Recherche Scientifique, Montpellier, France). Produced by Caitlin Sedwick and Ben Short. See the associated paper in JCB for details on the funding provided to support this original research. Subscribe to biosights via iTunes or RSS View biosights archive The Rockefeller University Press biosights@rockefeller.edu

How catastrophes help oocytes avoid disaster During meiosis, oocytes must attach homologous chromosomes to opposite spindle poles, but the cells take several hours to assemble a bipolar spindle. Gluszek et al. reveal that, in Drosophila oocytes, the microtubule catastrophe–promoting protein Sentin delays the formation of stable kinetochore–microtubule attachments until spindle assembly is complete, thereby preventing homologous chromosomes from incorrectly attaching to the same spindle pole. This biosights episode presents the paper by Głuszek et al. from the December 21st, 2015, issue of The Journal of Cell Biology and includes an interview with the paper's senior author, Hiroyuki Ohkura (University of Edinburgh, Edinburgh, Scotland, UK). Produced by Caitlin Sedwick and Ben Short. See the associated paper in JCB for details on the funding provided to support this original research. Subscribe to biosights via iTunes or RSS View biosights archive The Rockefeller University Press biosights@rockefeller.edu

Cells migrate on the crest of a wave Cells move through complex 3D environments in vivo, but studying 3D modes of migration in vitro remains a major challenge. Guetta-Terrier et al. examine the movement of cells along suspended nanofibers that mimic 3D fibrillar matrices and find that their migration is guided by fin-like protrusions that propagate away from the cell body to extend the leading edge. This biosights episode presents the paper by Guetta-Terrier et al. from the November 9th, 2015, issue of The Journal of Cell Biology and includes an interview with the paper's corresponding authors, Benoit Ladoux (National University of Singapore and Institut Jacques Monod, Paris, France) and Nils Gauthier (National University of Singapore). Produced by Caitlin Sedwick and Ben Short. See the associated paper in JCB for details on the funding provided to support this original research. Subscribe to biosights via iTunes or RSS View biosights archive The Rockefeller University Press biosights@rockefeller.edu

CLIP-170 tips its hand in viral transport After entering a cell, many viruses move toward the nucleus by binding to the microtubule-based motor protein dynein. Jovasevic et al. reveal, however, that herpes simplex virus must first associate with the plus ends of microtubules in a process that requires the dynein accessory factor dynactin and the plus end tracking proteins EB1 and CLIP-170. This biosights episode presents the paper by Jovasevic et al. from the October 26th, 2015, issue of The Journal of Cell Biology and includes an interview with the paper's corresponding author, Derek Walsh (Northwestern University, Chicago, IL). Produced by Caitlin Sedwick and Ben Short. See the associated paper in JCB for details on the funding provided to support this original research. Subscribe to biosights via iTunes or RSS View biosights archive The Rockefeller University Press biosights@rockefeller.edu  

Maintaining the link between spindle and furrow position The cytokinetic cleavage furrow must be carefully aligned with the spindle midzone during asymmetric cell division. Pacquelet et al. discover a pathway that maintains the connection between spindle and furrow position in one-cell C. elegans embryos by inhibiting the accumulation of myosin at the anterior cortex during cytokinesis. This biosights episode presents the paper by Pacquelet et al. from the September 28, 2015, issue of The Journal of Cell Biology and includes an interview with the paper's corresponding author, Anne Pacquelet (Centre National de la Recherche Scientifique and Institut de Génétique et Développement de Rennes, France). Produced by Caitlin Sedwick and Ben Short. See the associated paper in JCB for details on the funding provided to support this original research. Subscribe to biosights via iTunes or RSS View biosights archive The Rockefeller University Press biosights@rockefeller.edu

Pushing the envelope on spindle assembly During mitosis, numerous proteins accumulate around the mitotic spindle to help it assemble and segregate sister chromatids correctly. Schweizer et al. reveal that a membranous spindle envelope facilitates the accumulation of these proteins by excluding large organelles from the spindle region. This biosights episode presents the paper by Schweizer et al. from the August 31st, 2015, issue of The Journal of Cell Biology and includes an interview with the paper's senior author, Helder Maiato (University of Porto, Porto, Portugal). Produced by Caitlin Sedwick and Ben Short. See the associated paper in JCB for details on the funding provided to support this original research. Subscribe to biosights via iTunes or RSS View biosights archive The Rockefeller University Press biosights@rockefeller.edu

Endocytosis brings closure to epithelial wounds Epithelial cells bordering a wound respond by forming two types of actin-based structure: dynamic membrane protrusions that help the cells crawl into the wound and/or seal it and an actomyosin cable that encircles the wound and closes it like a purse string. Matsubayashi et al. reveal that the endocytic remodeling of intercellular adherens junctions promotes Drosophila epidermal wound healing by coordinating the activity of multiple actin regulators at the wound edge. This biosights episode presents the paper by Matsubayashi et al. from the August 3rd, 2015, issue of The Journal of Cell Biology and includes an interview with the paper's senior author, Tom Millard (University of Manchester, Manchester, UK). Produced by Caitlin Sedwick and Ben Short. See the associated paper in JCB for details on the funding provided to support this original research. Subscribe to biosights via iTunes or RSS View biosights archive The Rockefeller University Press biosights@rockefeller.edu

Interphase centrosomes flare up Centrosomes undergo dramatic changes in size and structure during the rapid cell cycles of early Drosophila embryos. Lerit et al. reveal that a scaffold formed by the proteins centrosomin and PLP is required to maintain the activity of interphase centrosomes, which is essential for nuclear spacing and proper chromosome segregation. This biosights episode presents the paper by Lerit et al. from the July 6th, 2015, issue of The Journal of Cell Biology and includes an interview with two of the paper's authors, Dorothy Lerit and Nasser Rusan (National Heart, Lung, and Blood Institute, Bethesda, MD). Produced by Caitlin Sedwick and Ben Short. See the associated paper in JCB for details on the funding provided to support this original research. Subscribe to biosights via iTunes or RSS View biosights archive The Rockefeller University Press biosights@rockefeller.edu

Melanosomal cargoes BLOC'd off from alternate routes The BLOC-2 complex contains three subunits encoded by genes mutated in Hermansky-Pudlak syndrome, a disease caused by defects in the trafficking pathways that form melanosomes and other lysosome-related organelles. Dennis et al. reveal that the BLOC-2 complex promotes the delivery of melanosomal cargo by targeting recycling endosomal tubules to maturing melanosomes. This biosights episode presents the paper by Dennis et al. from the May 25, 2015, issue of The Journal of Cell Biology and includes an interview with one of the paper's senior authors, Michael Marks (University of Pennsylvania, Philadelphia, PA). Produced by Caitlin Sedwick and Ben Short. See the associated paper in JCB for details on the funding provided to support this original research. Subscribe to biosights via iTunes or RSS View biosights archive The Rockefeller University Press biosights@rockefeller.edu

Formin' actin at adherens junctions Actin assembly promotes the formation of intercellular adherens junctions, but the role of actin-nucleating formin proteins in this process remains unclear. Grikscheit et al. reveal that, in breast epithelial cells cultured in 3D, the formin FMNL2 stimulates junctional actin assembly downstream of the small GTPase Rac1. This biosights episode presents the paper by Grikscheit et al. from the May 11, 2015, issue of The Journal of Cell Biology and includes an interview with the paper's senior author, Robert Grosse (University of Marburg, Marburg, Germany). Produced by Caitlin Sedwick and Ben Short. See the associated paper in JCB for details on the funding provided to support this original research. Subscribe to biosights via iTunes or RSS View biosights archive The Rockefeller University Press biosights@rockefeller.edu

A motif that helps myosin II-B lead from behind Myosin II-A and myosin II-B play distinct roles in establishing the front–back polarity of migrating mesenchymal cells. Juanes-Garcia et al. identify a short, serine-rich motif in the non-helical tail domain of myosin II-B that enables this isoform to form stable actomyosin bundles that define the cell rear. This biosights episode presents the paper by Juanes-Garcia et al. from the April 13, 2015, issue of The Journal of Cell Biology and includes an interview with the paper's senior author, Miguel Vicente-Manzanares (Universidad Autonoma de Madrid, Madrid, Spain). Produced by Caitlin Sedwick and Ben Short. See the associated paper in JCB for details on the funding provided to support this original research. Subscribe to biosights via iTunes or RSS View biosights archive The Rockefeller University Press biosights@rockefeller.edu

PAPC separates tissues at a Snail's pace Brachet's cleft separates the ectoderm and mesoderm of early Xenopus and zebrafish embryos. Luu et al. reveal that, in conjunction with the transcription factor Snail1, the protocadherin PAPC promotes tissue separation by down-regulating planar cell polarity proteins at the ectoderm-mesoderm boundary. This biosights episode presents the paper by Luu et al. from the March 16, 2015, issue of The Journal of Cell Biology and includes an interview with one of the paper's senior authors, Rudolf Winklbauer (University of Toronto, Toronto, Canada). Produced by Caitlin Sedwick and Ben Short. See the associated paper in JCB for details on the funding provided to support this original research. Subscribe to biosights via iTunes or RSS View biosights archive The Rockefeller University Press biosights@rockefeller.edu

Filopodia point the way for haptotaxis Migrating fibroblasts maintain or change their direction by branching off new lamellipodia from existing protrusions at the cell's leading edge. Johnson et al. reveal that filopodial protrusions initiate and orient these lamellipodia, helping fibroblasts navigate gradients of immobilized guidance cues. This biosights episode presents the paper by Johnson et al. from the February 16, 2015, issue of The Journal of Cell Biology and includes an interview with the paper's senior author, Jason Haugh (North Carolina State University, Raleigh, NC). Produced by Caitlin Sedwick and Ben Short. See the associated paper in JCB for details on the funding provided to support this original research. Subscribe to biosights via iTunes or RSS View biosights archive The Rockefeller University Press biosights@rockefeller.edu

Tubulin transport pumps up cilia The assembly of cilia and flagella requires the delivery of large amounts of tubulin to the growing ends of the organelles' microtubules. Craft et al. reveal that tubulin loading onto intraflagellar transport particles is specifically upregulated in growing cilia. This biosights episode presents the paper by Craft et al. from the January 19, 2015, issue of The Journal of Cell Biology and includes an interview with the paper's senior author, Karl Lechtreck (University of Georgia, Athens, GA). Produced by Caitlin Sedwick and Ben Short. See the associated paper in JCB for details on the funding provided to support this original research. Subscribe to biosights via iTunes or RSS View biosights archive The Rockefeller University Press biosights@rockefeller.edu

Osmotic gradient is just the tonic for wounded epithelia Rapid wound repair is generally thought to be initiated by intrinsic cues, such as changes in the structure or mechanics of damaged tissues. Gault et al. reveal that an extrinsic signal — the osmolarity of the external environment — can stimulate wound closure in zebrafish by inducing epithelial cell migration. This biosights episode presents the paper by Gault et al. from the December 22, 2014, issue of The Journal of Cell Biology and includes an interview with the paper's senior author, Philipp Niethammer (Memorial Sloan Kettering Cancer Center, New York). Produced by Caitlin Sedwick and Ben Short. See the associated paper in JCB for details on the funding provided to support this original research. Subscribe to biosights via iTunes or RSS View biosights archive The Rockefeller University Press biosights@rockefeller.edu

Dynein helps centrioles stick together Dynein has numerous functions in mitosis, but the function of the motor complex's light intermediate chains is poorly understood. Jones et al. reveal that dynein's light intermediate chains are required to maintain centrosome integrity during mitosis, preventing the premature separation of mother-daughter centrioles and the formation of multipolar spindles. This biosights episode presents the paper by Jones et al. from the November 24, 2014, issue of The Journal of Cell Biology and includes an interview with the paper's senior authors, Viki Allan and Sarah Woolner (University of Manchester, UK). Produced by Caitlin Sedwick and Ben Short. See the associated paper in JCB for details on the funding provided to support this original research. Subscribe to biosights via iTunes or RSS View biosights archive The Rockefeller University Press biosights@rockefeller.edu

Cdc42 prompts a change of heart The apical surfaces of polarized epithelia are covered by short, actin-rich protrusions called microvilli, but what happens to these structures when cells detach from a monolayer during development or disease is unclear. Klingner et al. reveal that non-confluent epithelial cells form longer, more dynamic microvilli on their apical surface that connect to a cortical actomyosin network. This biosights episode presents the paper by Klingner et al. from the October 13, 2014, issue of The Journal of Cell Biology and includes an interview with the paper's senior author, Roland Wedlich-Söldner (University of Münster, Germany). Produced by Caitlin Sedwick and Ben Short. See the associated paper in JCB for details on the funding provided to support this original research. Subscribe to biosights via iTunes or RSS View biosights archive The Rockefeller University Press biosights@rockefeller.edu

Cdc42 prompts a change of heart The Drosophila heart is a simple tubular structure with a central lumen. Vogler et al. reveal that the small GTPase Cdc42 and actin-nucleating formin proteins promote lumen formation by regulating the dynamics of non-muscle myosin in cardioblasts during heart morphogenesis. This biosights episode presents the paper by Vogler et al. from the September 29, 2014, issue of The Journal of Cell Biology and includes an interview with two of the paper's authors, Georg Vogler and Rolf Bodmer (Sanford-Burnham Medical Research Institute, La Jolla, CA). Produced by Caitlin Sedwick and Ben Short. See the associated paper in JCB for details on the funding provided to support this original research. Subscribe to biosights via iTunes or RSS View biosights archive The Rockefeller University Press biosights@rockefeller.edu

Deploying exosomes in a battle of the sexes The paired accessory glands of male Drosophila secrete multiple signaling factors into the seminal fluid that promote reproductive success by altering the recipient female's physiology and behavior. This biosights episode presents the paper by Corrigan et al. from the September 1, 2014, issue of The Journal of Cell Biology and includes an interview with corresponding author Alexander Bershadsky (Weizmann Institute, Israel, and Mechanobiology Institute, National University of Singapore). Produced by Caitlin Sedwick and Ben Short. See the associated paper in JCB for details on the funding provided to support this original research. Subscribe to biosights via iTunes or RSS View biosights archive The Rockefeller University Press biosights@rockefeller.edu

Rok keeps its finger on the pulse of apical constriction Early in Drosophila embryogenesis, contractile pulses of myosin assembly and disassembly constrict the apical domains of a group of epithelial cells to drive their invagination into a ventral furrow. Vasquez et al. reveal that Rho kinase and myosin phosphatase dynamically regulate these myosin pulses and that the stepwise constriction resulting from this helps maintain tissue integrity during epithelial invagination. This biosights episode presents the paper by Vasquez et al. from the August 4, 2014, issue of The Journal of Cell Biology and includes an interview with two of the paper's authors, Claudia Vasquez and Adam Martin (Massachusetts Institute of Technology, Cambridge, MA). Produced by Caitlin Sedwick and Ben Short. See the associated paper in JCB for details on the funding provided to support this original research. Subscribe to biosights via iTunes or RSS View biosights archive The Rockefeller University Press biosights@rockefeller.edu

The fluid dynamics of collective cell migration During development and tumor metastasis, cells prepare to migrate by undergoing an epithelial-to-mesenchymal transition that loosens their connections to neighboring cells. But some cell types then migrate en masse to their final destinations, indicating that their intercellular adhesions aren't disrupted completely. Kuriyama et al. reveal that the phospholipid lysophosphatidic acid promotes the collective migration of Xenopus neural crest cells by downregulating the surface expression of N-cadherin, granting the cells fluid-like properties that enhance their movement through embryonic tissues. This biosights episode presents the paper by Kuriyama et al. from the July 7, 2014, issue of The Journal of Cell Biology and includes an interview with senior author Roberto Mayor (University College London, UK). Produced by Caitlin Sedwick and Ben Short. See the associated paper in JCB for details on the funding provided to support this original research. Subscribe to biosights via iTunes or RSS View biosights archive The Rockefeller University Press biosights@rockefeller.edu