RIC8 guanine nucleotide exchange factor B (RIC8B)

RIC8 guanine nucleotide exchange factor B (RIC8B) is a cytosolic protein acting as a chaperone and a guanine nucleotide exchange factor (GEF) for certain G protein alpha subunits, particularly Gαs and Gαolf[2][3]. It catalyzes the exchange of GDP for GTP on these Gα subunits prior to their assembly into heterotrimeric G proteins and supports their proper folding, cellular stability, and association with the plasma membrane[2][3]. RIC8B is essential in the regulation of G protein-coupled receptor (GPCR) signaling cascades, especially in odorant signal transduction within olfactory sensory neurons, where it mediates Gαolf folding and subsequent cAMP accumulation[2][3]. RIC8B is structurally characterized by armadillo (ARM) and HEAT α-helical repeats forming a concave binding pocket that confers its specificity and chaperone activity for Gαs/olf-type proteins[2]. Dysfunction or mutation of RIC8B is associated with disorders including neurodevelopmental and neurodegenerative phenotypes[3]. No clinically approved drugs are reported to directly target RIC8B, and it is not established as a biomarker or a drug safety concern based on currently available data.

Other names

Chaperone Ric-8BhSynFLJ10620RIC8Brain synembrynSynembryn-Bbrain synembrinresistance to inhibitors of cholinesterase 8 homolog Bsynembryn-B