Functional analysis of the interface between the tandem C2 domains of synaptotagmin-1
| Autor: | R. Bryan Sutton, Xiaochu Lou, J. Michael Edwardson, Edwin R. Chapman, Zixuan He, Chantell S. Evans, Hua Bai, Pia Jeggle |
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| Přispěvatelé: | Apollo - University of Cambridge Repository |
| Jazyk: | angličtina |
| Rok vydání: | 2016 |
| Předmět: |
0301 basic medicine
Mutant Biology Neurotransmission Hippocampus Synaptic Transmission Synaptotagmin 1 Exocytosis 03 medical and health sciences Mice Animals Molecular Biology Mice Knockout Neurons Functional analysis Tandem Lipid bilayer fusion Articles Cell Biology 3. Good health Rats C2 Domains 030104 developmental biology Membrane Trafficking Synaptotagmin I Biophysics Mutagenesis Site-Directed Calcium Function (biology) |
| Zdroj: | Molecular Biology of the Cell |
| Popis: | Synaptotagmin (syt)-1 is a Ca2+ sensor that triggers rapid synaptic vesicle exocytosis. Mutations that disrupt physical interactions between the tandem Ca2+-sensing modules (C2 domains) of syt-1 disrupt regulated membrane fusion in reconstituted fusion reactions and in neurons. Hence contacts between these domains are important for function. C2 domains are widespread motifs that often serve as Ca2+-binding modules; some proteins have more than one copy. An open issue is whether these domains, when duplicated within the same parent protein, interact with one another to regulate function. In the present study, we address the functional significance of interfacial residues between the tandem C2 domains of synaptotagmin (syt)-1, a Ca2+ sensor for neuronal exocytosis. Substitution of four residues, YHRD, at the domain interface, disrupted the interaction between the tandem C2 domains, altered the intrinsic affinity of syt-1 for Ca2+, and shifted the Ca2+ dependency for binding to membranes and driving membrane fusion in vitro. When expressed in syt-1 knockout neurons, the YHRD mutant yielded reductions in synaptic transmission, as compared with the wild-type protein. These results indicate that physical interactions between the tandem C2 domains of syt-1 contribute to excitation–secretion coupling. |
| Databáze: | OpenAIRE |
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