RIM proteins and their role in synapse function.

Active zones are specialized areas of the plasma membrane in the presynaptic nerve terminal that mediate neurotransmitter release and synaptic plasticity. The multidomain proteins RIM1 and RIM2 are integral components of the cytomatrix at the active zone, interacting with most other active zone-enriched proteins as well as synaptic vesicle proteins. In the brain, RIMs are present in multiple isoforms (alpha, beta, gamma) diverging in their structural composition, which mediate overlapping and distinct functions. Here, we summarize recent findings about the specific roles of the various RIM isoforms in basic synaptic vesicle release as well as long- and short-term presynaptic plasticity.