background:
Rab3, a neural/neuroendocrine-specific member of the Rab family, is involved in Ca2+-regulated exocytosis (1-2). Rab3 functions in an inhibitory capacity by controlling the recruitment of secretory vesicles into a releasable pool at the plasma membrane. Rim (rab3 interacting molecule), a putative effector protein for Rab3s, is composed of an amino-terminal zinc-finger motif and carboxy-terminal PDZ and C2 domains. Rim exists as two variants, Rim1 and Rim2, produced by alternative splicing (3). Rim1 is expressed near the active zone at the synapse, where it interacts in a GTP-dependent manner with Rab3, located on synaptic vesicles (4). Therefore, Rim serves as a Rab3-dependent regulator of synaptic-vesicle fusion by forming a GTP-dependent complex between synaptic plasma membranes and docked synaptic vesicles (5). Both Rim1 and Rim2 can bind to cAMP-GEFII, which is a direct target of cAMP in regulated exocytosis and is responsible for cAMP-dependent, PKA-dependent exocytosis (3). Rim also localizes on the plasma membrane of INS-1E cells and pancreatic beta-cells. Rab3 binding domain of Rim enhances glucose-stimulated secretion in intact cells and Ca2+-stimulated exocytosis in permeabilized cells, suggesting that Rim may also play a regulatory role in insulin secretion (6).
Function:
RIM2 is a rab effector involved in exocytosis. It may act as scaffold protein. It is thought to be an effector protein for Rab3, binding to Rab3 on synaptic vesicles in a GTP dependent manner.
Subunit:
Interacts with RAB3A and RAB3B that have been activated by GTP-binding. Interacts with RAB3C, RAB3D and RAB26. Interacts with BZRAP1/RIMBP1 and RIMBP2. Interacts with PPFIA3 and PPFIA4. Interacts via its zinc finger with the first C2 domain of UNC13A. Forms a complex consisting of UNC13A, RIMS2 and RAB3A. Heterodimer with PCLO. Part of a ternary complex involving PCLO and EPAC2 (By similarity).
Subcellular Location:
Cell membrane; Peripheral membrane protein (By similarity). Cell junction, synapse (By similarity). Cell junction, synapse, presynaptic cell membrane; Peripheral membrane protein (By similarity).
Similarity:
Contains 2 C2 domains.
Contains 1 FYVE-type zinc finger.
Contains 1 PDZ (DHR) domain.
Contains 1 RabBD (Rab-binding) domain.
Database links:
UniProtKB/Swiss-Prot: Q9UQ26.2
Important Note:
This product as supplied is intended for research use only, not for use in human, therapeutic or diagnostic applications.
|
|
