Amit Chougule, Chunbin Zhang, Nickolas Vinokurov, Devin Mendez, Elizabeth Vojtisek, Chenjun Shi, Jitao Zhang, Joseph Gardinier
This study demonstrates that osteocytes’ expression of P2Y2 mediates actin polymerization and mitigates the anabolic response to fluid flow. In vivo studies also demonstrate that deletion of osteocytes’ P2Y2 receptor in mice enhances bone formation in response to treadmill exercise.
Posttranslational modifications play a crucial role in regulating autophagy and lysosome–related transcription factor TFEB. Huang et al. find the increase in intracellular lactate induces TFEB lactylation. Lactylation at K91 protects TFEB from WWP2-mediated ubiquitination and proteasomal degradation, thereby enhancing lysosomal activity and autophagy flux.
Daniel Ballmer, Hua Jane Lou, Midori Ishii, Benjamin E. Turk, Bungo Akiyoshi
Ballmer et al. investigate the role of Aurora B in regulating chromosome segregation in Trypanosoma brucei, whose kinetochores consist of unique proteins. They find that Aurora B activity is required for establishing stable kinetochore–microtubule attachments and promotes mitotic exit through phosphorylation of a Bub1-like protein.
Fernanda Cisneros-Soberanis, Eva L. Simpson, Alison J. Beckett, Nina Pucekova, Samuel Corless, Natalia Y. Kochanova, Ian A. Prior, Daniel G. Booth, William C. Earnshaw
Cisneros-Soberanis et al. use electron microscopy–based 3D reconstruction of entire mitotic cells to show that chromosomes progressively condense to a remarkable near-millimolar nucleosome concentration by late prometaphase. They maintain this plateau density through early anaphase and then expand in volume just before cell division is complete.
Marco Heydecker, Akiko Shitara, Desu Chen, Duy T. Tran, Andrius Masedunskas, Muhibullah S. Tora, Seham Ebrahim, Mark A. Appaduray, Jorge Luis Galeano Niño, Abhishek Bhardwaj, Kedar Narayan, Edna C. Hardeman, Peter W. Gunning, Roberto Weigert
Heydecker et al. use intravital subcellular microscopy to study the membrane remodeling in live mice. They show that this process requires the spatial and temporal coordination of two distinct force-generating modules composed of linear actin filaments assembled in a lattice and branched filaments organized in a network, respectively.
Ben Johnson, Maria Iuliano, TuKiet T. Lam, Thomas Biederer, Pietro V. De Camilli
The ER-anchored lipid transfer protein TMEM24/C2CD2L and its paralog C2CD2 mediate the formation of ER–plasma membrane junctions at sites of cell–cell contacts by interacting with band 4.1 family members and indirectly with cell adhesion proteins.
Fang et al. reveal that Kif6 and Kif9 of the kinesin-9 family play distinct roles in mammalian motile cilia. Kif6 appears to aid cargo transport along doublet microtubules to facilitate rotational polarizations of ependymal multicilia, whereas Kif9 fine-tunes ciliary beat on the central apparatus.
Anbing Shi discusses new work from Li and colleagues revealing that LYSMD proteins facilitate the development of lysosome-related organelles by activating Rab32-family GTPases.
Extracellular vesicles are known for intercellular signaling roles but can also serve to simply dispose of unwanted cargoes. In this issue, Bostelman and Broihier discuss new work from Rodal and colleagues that refutes prior work by showing that extracellular vesicles at Drosophila neuromuscular junctions are not required for signaling and instead likely serve a proteostasis role.
Eloïse Néel, Marioara Chiritoiu-Butnaru, William Fargues, Morgane Denus, Maëlle Colladant, Aurore Filaquier, Sarah E. Stewart, Sylvain Lehmann, Chiara Zurzolo, David C. Rubinsztein, Philippe Marin, Marie-Laure Parmentier, Julien Villeneuve
Néel et al. review how endolysosomes, positioned at the crossroads of multiple intracellular trafficking pathways, play critical roles in conventional and unconventional protein secretion.
