Ca2+-dependent, phospholipid-binding residues of synaptotagmin are critical for excitation-secretion coupling in vivo.

ABSTRACT: Synaptotagmin I is the Ca(2+) sensor for fast, synchronous release of neurotransmitter; however, the molecular interactions that couple Ca(2+) binding to membrane fusion remain unclear. The structure of synaptotagmin is dominated by two C(2) domains that interact with negatively charged membranes after binding Ca(2+). In vitro work has implicated a conserved basic residue at the tip of loop 3 of the Ca(2+)-binding pocket in both C(2) domains in coordinating this electrostatic interaction with anionic membranes. Although results from cultured cells suggest that the basic residue of the C(2)A domain is functionally significant, such studies provide contradictory results regarding the importance of the C(2)B basic residue during vesicle fusion. To directly test the functional significance of

SUBMITTER: Paddock BE 

PROVIDER: S-EPMC2949296 | biostudies-literature | 2008 Jul

REPOSITORIES: biostudies-literature