Regulator Of G Protein Signaling 19 (RGS19)

Sequence analysis predicted that GAIP is a 24.6-kD, hydrophilic protein that lacks a transmembrane domain and contains multiple potential phosphorylation sites. GAIP shares approximately 31% amino acid identity with regulator of G protein signaling-1 (RGS1) and -2 (RGS2); the 125-amino acid core domains of GAIP, RGS1, and RGS2 share approximately 64% homology.

Northern blot analysis detected a 1.6-kb GAIP transcript in lung, placenta, liver, heart, and pancreas, with almost no expression detected in brain, skeletal muscle, and kidney. Yeast 2-hybrid binding analyses showed that through its core domain, GAIP interacts strongly with GNAI3 and weakly with GNAI2, but does not interact with GNA11.