Synaptic transmission: Munc13 assembles onto PI(4,5)P₂-rich domains into trimers that cooperate to capture vesicles.

ABSTRACT: Munc13-1 is a key protein involved in priming synaptic vesicles for rapid release at the presynaptic plasma membrane. It was previously revealed that Munc13-1 cycles between at least two alternate conformations, an upright (open) molecular conformation organized as a trimer and a lateral (closed) conformation organized as a hexagon. Munc13 binds PI(4,5)P₂, a plasma membrane phospholipid essential for vesicle docking and fusion. We report that Munc13 is recruited to PI(4,5)P₂ domains induced by a Syntaxin-1A juxta-membrane peptide in supported bilayers. Statistical analysis of the copy numbers of Munc13 within the domains suggests that Munc13 exists in clusters of three molecules, i.e., it assembles into trimers. The trimeric clusters disappear with engineered interfac

SUBMITTER: Li F 

PROVIDER: S-EPMC12912961 | biostudies-literature | 2026 Feb

REPOSITORIES: biostudies-literature