Small G Protein Signaling Modulator 2 (SGSM2)

The deduced 1,051-amino acid SGSM2 protein contains an N-terminal RUN domain and a C-terminal TBC domain. Like SGSM1 and SGSM3, SGSM2 contains a RAP-interacting domain (RAPID) (amino acids 301-350), containing 5 blocks of conserved sequence following the RUN motif. Northern blot analysis detected variable expression of 6.0- and 9.4-kb SGSM2 transcripts in several human tissues. Mouse tissues showed a similar expression profile of Sgsm2, with evidence of splice variants.Endogenous Rab4 and Rab11 interacted with all of the SGSM proteins in the mouse neuroblastoma cell line; however, Rab3, Rab5, and Rab8 interacted only with SGSM1 and SGSM3.