Unique structural features of membrane-bound C-terminal domain motifs modulate complexin inhibitory function Academic Article uri icon

Overview

MeSH Major

  • Caenorhabditis elegans
  • Caenorhabditis elegans Proteins
  • Motor Disorders
  • Mutation, Missense
  • Nerve Tissue Proteins
  • Synaptic Transmission
  • Synaptic Vesicles

abstract

  • Complexin is a small soluble presynaptic protein that interacts with neuronal SNARE proteins in order to regulate synaptic vesicle exocytosis. While the SNARE-binding central helix of complexin is required for both the inhibition of spontaneous fusion and the facilitation of synchronous fusion, the disordered C-terminal domain (CTD) of complexin is specifically required for its inhibitory function. The CTD of worm complexin binds to membranes via two distinct motifs, one of which undergoes a membrane curvature dependent structural transition that is required for efficient inhibition of neurotransmitter release, but the conformations of the membrane-bound motifs remain poorly characterized. Visualizing these conformations is required to clarify the mechanisms by which complexin membrane interactions regulate its function. Here, we employ optical and magnetic resonance spectroscopy to precisely define the boundaries of the two CTD membrane-binding motifs and to characterize their conformations. We show that the curvature dependent amphipathic helical motif features an irregular element of helical structure, likely a pi-bulge, and that this feature is important for complexin inhibitory function in vivo.

publication date

  • May 24, 2017

Research

keywords

  • Academic Article

Identity

Language

  • eng

PubMed Central ID

  • PMC5442187

Digital Object Identifier (DOI)

  • 10.3389/fnmol.2017.00154

PubMed ID

  • 28596722

Additional Document Info

start page

  • 154

volume

  • 10