InterPro domain: IPR039032

RIM proteins are scaffolding proteins at the active zone which bind to several other presynaptic proteins. The long isoforms of RIM proteins, which contain N-terminal Rab3 and Munc13 interacting domains, as well as a central PDZ domain and two C-terminal C2 domains, are encoded by two genes, Rim1 and Rim2 [ 1 ]. They have multiple isoforms (alpha, beta, gamma) diverging in their structural composition, which mediate overlapping and distinct functions [ 2 , 3 ]. These isoforms are involved in determining Ca2+ channel density and vesicle docking at the presynaptic active zone [ 4 ].

This entry includes Rim and related proteins. In Caenorhabditis elegans Rim acts after vesicle docking likely via regulating priming [ 5 ].

1. RIM1 and RIM2 redundantly determine Ca2+ channel density and readily-releasable pool size at a large hindbrain synapse. J. Neurophysiol. 69, jn.00488.2014
2. RIM proteins and their role in synapse function. Biol. Chem. 391, 599-606
3. Redundant functions of RIM1alpha and RIM2alpha in Ca(2+)-triggered neurotransmitter release. EMBO J. 4, 5852-63
4. RIM determines Ca²+ channel density and vesicle docking at the presynaptic active zone. Neuron 25, 304-16
5. A post-docking role for active zone protein Rim. Nat. Neurosci. , 997-1005