SMALL G PROTEIN SIGNALING MODULATOR 2; SGSM2

Alternative titles; symbols

• KIAA0397

HGNC Approved Gene Symbol: SGSM2

Cytogenetic location: 17p13.3 Genomic coordinates (GRCh38): 17:2,336,491-2,381,073 (from NCBI)

▼ Cloning and Expression

By database searching with the sequence of small G protein signaling modulator-1 (SGSM1; 611417) as query, followed by RT-PCR and RACE of a human brain cDNA library, Yang et al. (2007) cloned SGSM2, which had previously been cloned and named KIAA0397 by Ishikawa et al. (1997). The deduced 1,051-amino acid SGSM2 protein contains an N-terminal RUN domain and a C-terminal TBC domain. Like SGSM1 and SGSM3 (611418), SGSM2 contains a RAP (see RAP1A, 179520)-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.

▼ Gene Function

Using immunoprecipitation and Western blot analyses of proteins expressed by transfected human embryonic kidney cells, Yang et al. (2007) showed that SGSM1, SGSM2, and SGSM3 coimmunoprecipitated with all RAP proteins examined, including RAP1A, RAP1B (179530), RAP2A (179540), and RAP2B (179541). Yang et al. (2007) also found that endogenous Rab4 (179511) and Rab11 (see RAB11A, 605570) interacted with all of the SGSM proteins in the mouse neuroblastoma cell line; however, Rab3 (see RAB3A, 179490), Rab5 (see RAB5A, 179512), and Rab8 (see RAB8A, 165040) interacted only with SGSM1 and SGSM3.

▼ Gene Structure

Yang et al. (2007) determined that the SGSM2 gene contains 23 exons.

▼ Mapping

By radiation hybrid analysis, Ishikawa et al. (1997) mapped the SGSM2 gene to chromosome 17. By genomic sequence analysis, Yang et al. (2007) localized the gene to 17p13.3.