Issues

Kaushik and Ladher discuss recent work from Nita and colleagues, describing how FGFR2 localization at primary cilia affects FGFR signalling and highlighting the role of the cilium in a disease-related context.

Sabina Elmi and Jesper Nylandsted highlight work by Williams and colleagues that provides new insight into the role of annexins in the repair of plasma membrane lesions.

Wang and Baehrecke discuss the conserved role of Atg9 in lysosome repair in C. elegans and human cells.

Hirano reviews mitotic genome folding with an emphasis on the mechanistic aspects of condensins, topoisomerase II, and histones.

Schaeffer et al. show that the centrosomal array of microtubules is positioned by the contraction of the actomyosin network and the reorganization of cell shape around the centrosome rather than centrosome displacement toward the cell center by a balance of forces along microtubules.

This study reveals that the kinase LKB1 is crucial for migration and nuclear positioning of specialized type of RGCs called F-RGCs. Its absence leads to misplacement, altered morphology, and increased cell death, highlighting that different RGC types can use distinct migration programs.

Cytokinesis is tightly regulated in metazoans. Adhikary et al. show that LIN-5/GPR-1/2 complexes present at the polar and lateral regions of the cell membrane facilitate the accumulation of contractile ring components at furrow formation and stabilize them in the midbody, thus aiding in various cytokinesis processes.

Osteoclast fusion requires decreased PM tension, facilitated by reduced ezrin expression and membrane-to-cortex attachment. Lower PM tension promotes invadosome formation and cell–cell fusion, while higher PM tension inhibits fusion. These findings highlight the role of membrane mechanics in osteoclast fusion.

Jung and Kim et al. show that combined ALDH9A1 and FANCD2 deficiency leads to genomic instability, decreased cell survival, and tumorigenesis. Loss of ATP13A3, a polyamine transporter, rescues cellular growth, implicating aminoaldehydes in the creation of DNA damage, which necessitates repair by the Fanconi anemia pathway.

In mouse embryonic stem cells, the kinesin-13 member KIF2A converts from a microtubule depolymerase during metaphase to a microtubule stabilizer during cytokinesis, due to the inhibition of ATPase activity and a preference for compacted lattices. KIF2A-mediated microtubule stabilization prolongs cytokinesis to maintain stem cell pluripotency.

Lipid homeostasis depends on membrane contact sites (MCS). This study shows that the integrity of multiple ER MCS requires Pex30 binding to phosphatidic acid via its dysferlin domain. The authors also show that Pex30 activity is regulated by phosphorylation in response to metabolic cues.

In this study, we show that Pex30 dysferlin domain binds PA through its two hydrophobic regions adjacent to beta sheets. We propose that, PA, a precursor for neutral lipids, recruits Pex30 at ER subdomains that plays a critical role in LD biogenesis.

The precise roles of the mitophagy receptors BNIP3 and NIX remain unclear. This study demonstrates that they are required for tight attachment and expansion of the isolation membrane along the mitochondrial surface, supporting a characteristic morphologic feature of the mitophagy.

Nita et al. show that the FGFR2 localizes to primary cilia of the developing mouse tissues and in vitro cells; they identify the molecular mechanism of this action, and show its critical function in FGFR2 signaling.

Peng Huang et al. find that the ciliary kinesin OSM-3 exhibits an extended, active conformation at the ciliary base and middle segments. Their results indicate the NEK family kinases and PP2A phosphatase collaborate through a phosphorylation-mediated mechanism to regulate the regional motility of ciliary kinesin.

Kinesin-1 alternately moves its two motor domains (heads) to walk along the microtubule. Makino et al. demonstrate that the detached head cannot rebind to the rear binding site because of an intolerable increase in tension, thus ensuring forward stepping after ATP binding.

This study provides insights into how cargo adaptors bind myosin V. Genetics, cell-based assays, cryo-EM, and AlphaFold reveal that the vacuole-specific adaptor uses a handhold mechanism to attach to two areas on the myosin-V tail. Moreover, evidence is presented that other adaptors use a similar strategy.

We discovered that silencing the phosphatidylinositol (PI) 3-phosphatase, MTMR, disrupts the PM localization of PtdSer and KRAS. We propose a model, where MTMR loss depletes PM PI needed for PM PI4P synthesis, an essential phospholipid for PM PtdSer enrichment, thereby impairing KRAS PM localization.

Human cells repair plasma membrane lesions in a two-step process. After a membrane scab forms at the lesion site, the scab is shed as annexin-containing extracellular vesicles.

The PAX3-FOXO1 fusion gene suppresses TGFβ signaling and cell–ECM interactions by stimulating nitric oxide synthesis in fusion-positive rhabdomyosarcoma. This finding reveals that the subtype-defining molecule promotes anchorage independence and may contribute to distinct clinical behavior of rhabdomyosarcoma subtypes, suggesting subtype-specific therapies in this pediatric sarcoma.

This study examines how RIM and MUNC13 synergistically regulate DCV exocytosis. It demonstrates that MUNC13 is essential for DCV secretion, while RIM prevents its degradation. Key membrane-binding domains of RIM and MUNC13 play differing roles, revealing distinct mechanisms from synaptic vesicle release.