bims-migras 2026-01-11 papers

Issue of 2026–01–11
two papers selected by
Cliff Dominy

Nat Commun. 2026 Jan 07.

O-GlcNAcylation of AMFR stabilizes TSPAN4 to regulate migrasome formation for viral release.

Linghui Yu, Jiajia Li, Yiyang Han, Xiao Yang, Yu Fu, Weiyi Zhang, Yaming Jiu, Linling Cheng, Binbin Ding.

Migrasomes are migration-dependent organelles, serving as delivery packets to mediate release of cytoplasmic contents. Tetraspanin 4 (TSPAN4) acts as a marker for migrasomes and is essential for their formation. However, the regulatory mechanism(s) underlying TSPAN4-mediated migrasome biogenesis and its physiological functions remain to be elucidated. Here, we identified AMFR, an ER-resident E3 ligase, regulates migrasome formation through catalyzing the K48-linked polyubiquitination of TSPAN4 for degradation. Further, O-GlcNAcylation of AMFR by OGT at threonine 643 disrupts AMFR-TSPAN4 interactions, thereby stabilizing TSPAN4 and promoting migrasome formation. Additionally, viruses dynamically regulate migrasome formation by modulating AMFR O-GlcNAcylation and TSPAN4 ubiquitination. During the early stages of VSV or HSV-1 infection, viruses enhance migrasome formation and exploit these structures to spread among neighboring cells, whereas abolish migrasome formation during the late stages of infection. Our findings reveal a negatively regulatory mechanism governing migrasome biogenesis, and highlight how VSV and HSV-1 manipulate this process to facilitate their release.

DOI: https://doi.org/10.1038/s41467-025-68220-3

Mol Brain. 2026 Jan 09.

Primary cortical neurons precipitate and extrude large mitochondria-associated calcium-phosphate sheets with a bone-precursor-like ultrastructure.

Erik D Anderson, Christopher A Cronkite, Philip R Baldwin, Carlota P Abella, Joseph G Duman, Ashleigh N Simmonds, M Neal Waxham, Kimberley F Tolias, Steven J Ludtke.

Calcium-phosphate (CaP) is a ubiquitous inorganic compound that plays an important structural role in healthy bone and teeth formation, but its pathologic buildup can occur in dyshomeostatic calcium disorders like Alzheimer's disease and Leigh syndrome. The nexus of pathologic extracellular CaP in the nervous system is not well understood, but prior evidence suggests mitochondria could be a source. We have observed mitochondria-sized sheet-like CaP aggregates within functional wild type cortical neuron cultures at 1 and 20 days in vitro. Neurons were extracted from embryonic day 18 (E18) rat embryos following standard protocols to study neuronal structure and function. We have used a combination of cryo-ET, cryo-CLEM, and LDSAED to demonstrate that these aggregates are octacalcium phosphate-like, are associated with mitochondria, and that at least a portion are extruded via migrasomes. Visually similar aggregates were previously observed in Huntington's disease model neurons, but in that study they were not observed in WT controls. These findings show that this CaP aggregation process occurs routinely in WT neurons and may reveal an important link for how mitochondria may participate in calcification, highlighting them as potential therapeutic targets in neurological disorders characterized by pathological calcification, such as Alzheimer's disease.

Keywords: Calcium-phosphate; Cryo-CLEM; Cryo-ET; LDSAED; Migrasomes; Mitochondria; Neurons

DOI: https://doi.org/10.1186/s13041-025-01272-0