Alternative titles; symbols
HGNC Approved Gene Symbol: SNTG2
Cytogenetic location: 2p25.3 Genomic coordinates (GRCh38): 2:950,849-1,367,613 (from NCBI)
Syntrophins, such as SNTG2, are cytoplasmic peripheral membrane proteins that bind to the C-terminal domains of several dystrophin (300377) isoforms and to other dystrophin-related proteins (Piluso et al., 2000).
By searching an EST database using mouse and human syntrophins as probes, followed by screening human fetal brain and neuronal precursor cell cDNA libraries, Piluso et al. (2000) cloned SNTG1 (608714) and SNTG2. The deduced 539-amino acid SNTG2 protein has a calculated molecular mass of 60.1 kD. Syntrophins typically contain 2 pleckstrin (173570) homology (PH) domains, a PDZ domain that bisects the first PH domain, and a C-terminal 'syntrophin unique' (SU) domain that mediates dystrophin binding. SNTG1 and SNTG2 share significant similarity with other syntrophins in the PDZ domain, lower similarity in the PH domains, and weak similarity in the SU domain. In addition, SNTG1 and SNTG2 have an ATP/GTP-binding site motif A (P loop) and several potential phosphorylation sites. Northern blot analysis detected broad but weak expression of SNTG2. By sequencing SNTG2 clones and by PCR of human brain cDNA, Piluso et al. (2000) identified alternatively spliced SNTG2 variants. In situ hybridization and immunohistochemical analysis of rat central nervous system showed widespread distribution of SNTG1 and SNTG2 throughout several cerebral and spinal areas. Transcripts for both SNTG1 and SNTG2 were localized in the perikaryon and proximal portion of neuronal processes. Immunohistochemical analysis also detected SNTG2, but not SNTG1, at the sarcolemma of all human muscle fibers. A normal plasmalemmal signal was observed in patients with neurogenic atrophy, but SNTG2 was absent or severely reduced in Duchenne muscular dystrophy (310200) patients lacking dystrophin. SNTG2 was localized at cardiomyocyte membranes in 2 biopsy specimens.
By pull-down assays of recombinant proteins expressed in COS-7 cells and by yeast 2-hybrid analysis, Piluso et al. (2000) showed that SNTG2 bound to the C termini of dystrophin, alpha-dystrobrevin (601239), and beta-dystrobrevin (602415).
Piluso et al. (2000) determined that the SNTG2 gene contains at least 17 exons.
By radiation hybrid analysis, Piluso et al. (2000) mapped the SNTG2 gene to chromosome 2p25.
Piluso, G., Mirabella, M., Ricci, E., Belsito, A., Abbondanza, C., Servidei, S., Puca, A. A., Tonali, P., Puca, G. A., Nigro, V. Gamma-1- and gamma-2-syntrophins, two novel dystrophin-binding proteins localized in neuronal cells. J. Biol. Chem. 275: 15851-15860, 2000. [PubMed: 10747910] [Full Text: https://doi.org/10.1074/jbc.M000439200]