Complexin is able to bind to SNARE core complexes in different assembled states with distinct affinity.
The formation of the functional SNARE complex in vivo is central to the fast neurotransmitter release at the neuronal terminal. Numerous studies revealed that this process involves progressive assembly of an alpha-helical bundle and is dynamically reversible. So far many proteins directly or indirectly take part in this process. Complexin, one of such factors, has revealed rapid association with the SNARE complex, however, whether or not complexin can interact with partially assembled SNARE complex is critical and yet unknown. Here, we present evidence that complexin is able to bind to various mutant versions of the SNARE complex mimicking its quaternary structure at different assembly stages. In addition, the affinity of complexin for the SNARE complex is correlated with the extent to which the SNARE complex is assembled. These results suggest that complexin is able to bind to SNARE complex before its complete formation.
Liu
Jingguo
J
Department of Biological Sciences and Biotechnology, State-Key Laboratory of Biomembrane and Membrane Biotechnology, Tsinghua University, Beijing 100084, China.
Guo
Ting
T
Wei
Yong
Y
Liu
Ming
M
Sui
Sen-Fang
SF
D033942:Adaptor Proteins, Vesicular Transport; D000818:Animals; D001667:Binding, Competitive; D031541:Fluorescence Resonance Energy Transfer; D008164:Luminescent Proteins / Q000235:genetics / Q000378:metabolism; D008856:Microscopy, Fluorescence; D009154:Mutation; D009419:Nerve Tissue Proteins / Q000235:genetics / Q000378:metabolism*; D016716:PC12 Cells; D010446:Peptide Fragments / Q000235:genetics / Q000378:metabolism; D011485:Protein Binding; D051381:Rats; D050600:SNARE Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D050825:Synaptosomal-Associated Protein 25 / Q000235:genetics / Q000378:metabolism; D014162:Transfection
D033942:Adaptor Proteins, Vesicular Transport; D008164:Luminescent Proteins; D009419:Nerve Tissue Proteins; D010446:Peptide Fragments; D050600:SNARE Proteins; C494210:Snap25 protein, rat; D050825:Synaptosomal-Associated Protein 25; C095993:complexin II