Issues

Lebek and Campellone preview work from Jarsch et al., which shows that the sorting nexin SNX9 drives filopodial assembly.

Parton et al. discuss how the proteins of caveolae, and the architecture of the domain, can concentrate specific lipids in caveolae. They propose that disassembly of caveolae in response to cellular stressors releases specialized lipids to modulate signaling.

Silva et al. demonstrate that distinct cohesin complexes are essential for sister chromatid cohesion and genome folding in mammalian oocytes. Scc1-cohesin is required for chromatin loops while Rec8-cohesin mediates bivalent cohesion. Wapl-mediated release of Scc1-cohesin is required for accurate meiosis I chromosome segregation and promotes production of euploid eggs.

Golenberg et al. report a citrullination-deficient zebrafish and demonstrate a role for Padi2 in fin wound responses and regeneration. This work identifies a distinct population of cells within the regenerative notochord bead that exhibits wound-induced histone citrullination.

Jarsch et al. combine a cell-free system of filopodia-like structures with a phage display phenotypic screen of antibody-mediated inhibition. They find a role for SNX9 in making filopodial actin bundles and localize SNX9 to filopodia in cells hijacked by the human pathogen Chlamydia trachomatis.

Cruz-Garcia et al. show that production of ROS upon nutrient starvation in yeast promotes secretion of antioxidants and the signaling protein Acb1. These secreted proteins are necessary to maintain cell viability till cells return to favorable growth conditions.

Centrosomes withstand microtubule-mediated forces during spindle assembly, yet they are disassembled by similar forces during mitotic exit. Mittasch et al. use nanorheology to probe the material properties of centrosomes and how they change during the cell cycle. In anaphase, the centrosome scaffold becomes weak and brittle, thus allowing force-induced disassembly.

Cairo et al. show that in S. cerevisiae meiosis, spindle checkpoint proteins Bub1 and Bub3 have a critical role in preventing chromosome missegregation and setting the normal duration of anaphase I and II onset by regulating the kinetochore-localization of Ipl1 and PP1.

Polyploid cells with extra centrosomes and extra DNA divide in a multipolar manner. Using Drosophila and cancer cells challenged in different ways and in silico modeling, Goupil et al. show that chromosomes act as a barrier inhibiting spindle pole coalescence and favoring multipolar spindle assembly.

Centromeres ensure faithful chromosome partition upon cell division. This work reveals a novel role for centromeres in establishing/maintaining stem cell identity. Centromeric proteins are asymmetrically incorporated on sister chromatids before asymmetric division of Drosophila germline stem cells, which allows for selective chromosome segregation.

Detyrosination is a frequent posttranslational modification of long-lived microtubules that inhibits microtubule depolymerase activity in vitro. Ferreira et al. combine manipulation of tubulin tyrosine ligase and carboxypeptidase (Vasohibins-SVBP) activities with state-of-the-art microscopy in human cells to show that α-tubulin detyrosination allows centromeric MCAK to discriminate between correct and incorrect kinetochore–microtubule attachments and ensure mitotic fidelity.

Using an in vivo model of DNA damage involving Senataxin knockout mice along with in vitrogenotoxic treatments, Subramanian et al. identify a DNA damage response in oocytes that builds slowly following damage induction and is mediated by increased APC-Cdh1–mediated cyclin B1 proteolysis.

The plasticity of cancer cells depends on numerous factors that distinguish them from normal cells. Proteins with a tumor cell–selective killing activity offer powerful tools to uncover fundamental differences. Dziengelewski et al. show that one such protein, the adenovirus E4orf4, subverts Par3 to deregulate nuclear mechanics.

ER arrival sites (ERAS) that capture retrograde Golgi-to-ER COPI vesicles have not been well characterized. Roy Chowdhury et al. use the budding yeast Pichia pastoris to show that ERAS are physically and functionally linked to ER exit sites (ERES).

Mitochondria form a network that is constantly remodeled by fission and fusion. Abrisch et al. show that fission and fusion machineries converge at ER membrane contact sites (MCSs) to provide a unified platform where fission and fusion are coordinated to balance mitochondrial dynamics and morphology.

This study shows that FXR1 forms condensates in muscle cells. FXR1 alternative splicing during myogenesis alters the properties of an intrinsically disordered domain and influences the properties of condensates. This study links developmental control of RNA splicing to regulation of biomolecular condensation for muscle formation.

Chorlay and Thiam show that the binding of amphipathic helices to model lipid droplets depends on the neutral lipid composition. The phospholipid monolayer density simply regulates accessibility to the neutral lipids. The hydrophobic nature of the phospholipid packing voids is determinant to amphipathic helix recruitment.

Membrane protein polarity is essential for epithelial cell physiology. Levic et al. show that V-ATPase pump activity is required for biosynthetic sorting and trafficking of apical membrane proteins in the zebrafish intestine.

Stem cell activity has to be regulated throughout adult life to maintain tissue homeostasis. Li et al. find that the membrane-associated kinase Gilgamesh (Gish/CK1γ) restricts JNK signaling and Drosophila intestinal stem cell proliferation by phosphorylating and destabilizing Rho1.

Acid sphingomyelinase (ASMase) signals radiation-induced apoptosis from the plasma membrane in select cells. Ferranti et al. demonstrate that this signaling event is initiated by oxidation-dependent membrane damage that facilitates calcium influx and lysosome fusion with the plasma membrane to translocate ASMase to the cell surface.

Deng et al. report an essential role for the spectrin-based membrane skeleton in specifying cell shape by transmitting intracellular actomyosin force to cell membrane. Their findings uncover an essential mechanism that couples cell shape, cortical tension, and Hippo signaling in tissue morphogenesis.

Nijenhuis et al. developed a robust optogenetic toolbox to reversibly reposition organelles in populations of cells with minimal adverse effects on endogenous transport. This work opens new opportunities to dissect intracellular transport and spatial cell biology.