biosights: August 3, 2015 - Endocytosis brings closure to epithelial wounds

submitted by: JCB
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...

biosights: July 6, 2015 - Interphase centrosomes flare up

submitted by: JCB
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...

biosights: June 8, 2015 - Melanosomal cargoes BLOC'd off from alternate routes

submitted by: JCB
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...

biosights: May 11, 2015 - Formin' actin at adherens junctions

submitted by: JCB
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...

biosights: April 13, 2015 - A motif that helps myosin II-B lead from behind

submitted by: JCB
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...

biosights: March 16, 2015 - PAPC separates tissues at a Snail's pace

submitted by: JCB
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...

biosights: February 16, 2015 - Filopodia point the way for haptotaxis

submitted by: JCB
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...

biosights: January 19, 2015 - Tubulin transport pumps up cilia

submitted by: JCB
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)....

biosights: December 22, 2014 - Osmotic gradient is just the tonic for wounded epithelia

submitted by: JCB
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...

biosights: November 24, 2014 - Dynein helps centrioles stick together

submitted by: JCB
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...