Complexin-1 and synaptotagmin-1 compete for binding sites on membranes containing PtdInsP₂.

ABSTRACT: Complexin-1 is an essential protein for neuronal exocytosis that acts to depress spontaneous fusion events while enhancing evoked neurotransmitter release. In addition to binding soluble N-ethylmaleimide-sensitive factor attachment protein receptors, it is well established that complexin associates with membranes in a manner that depends upon membrane curvature. In the present work, we examine the membrane binding of complexin using electron paramagnetic resonance spectroscopy, fluorescence anisotropy, and total internal reflection fluorescence microscopy. The apparent membrane affinity of complexin is found to strongly depend upon the concentration of protein used in the binding assay, and this is a result of a limited number of binding sites for complexin on the membrane interface. Altho

SUBMITTER: Liang Q 

PROVIDER: S-EPMC9515229 | biostudies-literature | 2022 Sep

REPOSITORIES: biostudies-literature