People & Ideas
Gilles R.X. Hickson previews work from the Canman laboratory that finds that during cytokinesis, astral microtubules can serve as the source for assembling the midbody in cases when central spindle microtubules are absent.
Broussard and Green highlight work from Prechova et al. that identifies plectin as a mechanical integrator of cytoskeletal and adhesive networks for cellular tensional homeostasis.
Roney et al. review recent advances in how axonal endolysosomal trafficking, distribution, and functionality maintain distal degradation capacity in neuronal health and become disrupted in several neurodegenerative diseases.
Hirsch et al. found that genetic disruption of central spindle microtubule assembly in C. elegans embryos does not block cytokinesis or midbody assembly. These central spindle–independent midbodies appeared to form from astral microtubules, bundled by contractile ring constriction.
Glycosylphosphatidylinositol (GPI) anchors attach many proteins to the extracellular surface of the plasma membrane. Anchor synthesis occurs in the ER and requires phosphatidylethanolamine (PE). Toulmay et al. show that tubelike lipid transport proteins bring PE to the ER to support GPI anchor production.
Cardamone et al. characterize NEURL4 as a novel mitochondrial ART enzyme required for the maintenance of mtDNA integrity and the regulation of mitochondrial homeostasis through ADP-ribosylation.
Kinoshita et al. address the role of condensin I in chromosome assembly and identify two classes of mutations that cause hyper- and hypocompaction phenotypes in Xenopus egg extracts. The study reveals that a loop extrusion–independent mechanism also contributes to chromosome assembly and shaping.
Krishnan et al. use FISH to show that specific forms of RB induce changes in the organization of euchromatin and heterochromatin domains. These changes are visible under the microscope, occur after cell cycle arrest, are separable from senescence, and represent an E2F-independent activity of RB.
Karyopherin enrichment and compensation fortifies the nuclear pore complex against nucleocytoplasmic leakage
Kalita et al. show that cargo leakage out of the nucleus is prevented by an enrichment of different soluble receptors, termed “karyopherins,” that are able to compensate for one another to reinforce the nuclear pore complex barrier in vivo.
Kors et al. reveal that peroxisome–ER associations via the ACBD5-VAPB tether are regulated by phosphorylation and GSK3β in mammalian cells. Phosphorylation sites in the FFAT-like motif of ACBD5 affect the binding to VAPB—and thus peroxisome–ER contact sites—differently.
Lee and Levin investigate the question of how different stressors can drive divergent outputs from an active SAPK. The work describes the mechanism by which two forms of arsenic that both activate the yeast SAPK Hog1 differentially regulate the glycerol channel Fps1.
Drosophila tracheal terminal cells form subcellular tubes by invaginating their apical plasma membrane. Ríos-Barrera and Leptin show that late endosomes guide subcellular tube elongation toward the direction of cell growth by promoting F-actin organization between the tip of the subcellular tube and the advancing tip of the cell.
Campisi et al. uncover a new function of the core autophagy protein ATG9A in cell migration by demonstrating that ATG9A-positive vesicles are mobilized during chemotactic stimulation to participate in the extension and stabilization of leading-edge protrusions.
Prechova et al. demonstrate that cytolinker protein plectin is essential for the formation of the circumferential keratin rim, organization of radial keratin spokes, and desmosomal patterning. Thus, plectin controls cell cohesion and maintenance of epithelial stability.
SidK is introduced as a highly specific probe to visualize and quantify the proton-pumping vacuolar H+ATPases (V-ATPases) of mammalian cells and yeast.