Tex19.1 inhibits the N-end rule pathway and maintains acetylated SMC3 cohesin and sister chromatid cohesion in oocytes
Mammalian oocytes need to maintain sister chromatid cohesion during their prolonged postnatal development to faithfully segregate their chromosomes in meiosis. Reichmann et al. show that Tex19.1 modulates ubiquitin-dependent proteolysis and maintains the cohesive subpopulation of cohesin in postnatal mouse oocytes to prevent oocyte aneuploidy.
Wang et al. find that axonal radial contractility and local expansion control the retrograde trafficking of large cargoes. The periodic actomyosin-II network comprises NM-II filaments and F-actin rings. Loss of actomyosin-II–mediated radial contractility causes defects in axonal trafficking and stability, leading to degeneration.
Drosophila mushroom body γ-neurons offer an excellent model to study axonal growth. Yaniv et al. show that distinct actin elongation factors are employed in different developmental and cellular contexts, providing insights into the intrinsic growth capacity of neurons, a key determinant of regeneration following injury.
A key step in accurate chromosome segregation is the removal of the outer corona of the kinetochore when microtubules are attached. Auckland et al. reveal how CENP-F stabilizes kinetochore-microtubule attachments and limits dynein-mediated corona stripping.
Epithelial cell integrity and remodeling require proper actomyosin organization at adherens junctions through αE-catenin complexed with β-catenin. Sakakibara et al. show that afadin binds to αE-catenin complexed with β-catenin and enhances its F-actin–binding activity in a novel mechanism.
Grimsley-Myers et al. use mouse genetic and in vitro approaches to determine the role of the VE-cadherin-p120-catenin complex in vascular development. The results indicate that p120 stabilization of VE-cadherin is essential for vascular barrier function, whereas VE-cadherin endocytosis modulates polarized endothelial cell migration and angiogenesis.
Mitochondria exist as a dynamic network, and their fragmentation is associated with cell death. We found that mitochondria near the cell membrane injury site rapidly fragment and enable local signaling for repair. Cells lacking this machinery fail to repair, establishing that mitochondrial fragmentation enables cell survival.
The synaptonemal complex (SC) is a zipper-like protein structure that forms between paired homologous chromosomes during meiosis. Hurlock et al. discover two novel SC components, SYP-5 and SYP-6, in C. elegans and investigate their contributions in both limiting and promoting crossover formation.
Zhang et al. identify new synaptonemal complex (SC) central region proteins SYP-5 and SYP-6 in Caenorhabditis elegans and show that SC central region proteins form assembly units through stable interactions and weak interactions between the units that drive SC formation.
Cryo-EM reconstruction of a VPS13 fragment reveals a long groove to channel lipids between membranes
Structural studies by Li et al. suggest that in eukaryotes VPS13 and related proteins, like the autophagy protein ATG2, can act as bridges between organelle membranes to allow bulk lipid flow between them. Such a lipid transfer mechanism was previously known only in prokaryotes.