Rab3Abinding

Rab3Abinding refers to the molecular interactions between Rab3A, a small GTPase of the Rab family, and its binding partners. Rab3A cycles between a GDP-bound inactive state and a GTP-bound active state; recruitment of effector proteins to Rab3A depends on the GTP-bound conformation and regulates stages of the vesicle life cycle in neurons and other secretory cells.

On synaptic vesicles, Rab3A in its active form engages downstream effectors that influence neurotransmitter release. Classic Rab3A effectors include rabphilin-3A and the Rab3-interacting molecule family (Rim1 and Rim2). These interactions are typically Ca2+-regulated and participate in vesicle docking, priming, and the control of release probability. Hydrolysis of GTP to GDP leads to Rab3A dissociation and termination of the signaling event.

In addition to these effectors, Rab3Abinding also encompasses Rab3A-binding proteins such as RAB3BP (Rab3A-binding protein). Such proteins can modulate Rab3A signaling or link Rab3A to other cellular pathways. The exact roles of many Rab3A-binding partners remain the subject of ongoing research.

Rab3A binding is a key component of the broader Rab GTPase cycle that coordinates vesicle trafficking in secretory pathways. Disruption of Rab3A interactions can affect synaptic transmission and has been explored in studies of neuronal function and related disorders.