A Munc13/RIM/Rab3 tripartite complex: from priming to plasticity? EMBO J 2005 Aug 17;24(16):2839-50
Date
07/30/2005Pubmed ID
16052212Pubmed Central ID
PMC1187938DOI
10.1038/sj.emboj.7600753Scopus ID
2-s2.0-28844449520 (requires institutional sign-in at Scopus site) 212 CitationsAbstract
alpha-RIMs and Munc13s are active zone proteins that control priming of synaptic vesicles to a readily releasable state, and interact with each other via their N-terminal sequences. The alpha-RIM N-terminal sequence also binds to Rab3s (small synaptic vesicle GTPases), an interaction that regulates presynaptic plasticity. We now demonstrate that alpha-RIMs contain adjacent but separate Munc13- and Rab3-binding sites, allowing formation of a tripartite Rab3/RIM/Munc13 complex. Munc13 binding is mediated by the alpha-RIM zinc-finger domain. Elucidation of the three-dimensional structure of this domain by NMR spectroscopy facilitated the design of a mutation that abolishes alpha-RIM/Munc13 binding. Selective disruption of this interaction in the calyx of Held synapse decreased the size of the readily releasable vesicle pool. Our data suggest that the ternary Rab3/RIM/Munc13 interaction approximates synaptic vesicles to the priming machinery, providing a substrate for presynaptic plasticity. The modular architecture of alpha-RIMs, with nested binding sites for Rab3 and other targets, may be a general feature of Rab effectors that share homology with the alpha-RIM N-terminal sequence.
Author List
Dulubova I, Lou X, Lu J, Huryeva I, Alam A, Schneggenburger R, Südhof TC, Rizo JAuthor
Xuelin Lou PhD Professor in the Cell Biology, Neurobiology and Anatomy department at Medical College of WisconsinMESH terms used to index this publication - Major topics in bold
Amino Acid SequenceBinding Sites
Calorimetry
Electrophysiology
Escherichia coli
GTP-Binding Proteins
Glutathione Transferase
Humans
Models, Molecular
Molecular Sequence Data
Multiprotein Complexes
Mutagenesis
Nerve Tissue Proteins
Nuclear Magnetic Resonance, Biomolecular
Sequence Alignment
Synaptic Vesicles
rab3 GTP-Binding Proteins









