Regulatory Solute Carrier Protein Family 1, Member 1 (RSC1A1)

D-glucose is absorbed in the small intestine and kidney by sodium-coupled transport. SGLT1, SAAT1, and Hu14 are homologous integral membrane proteins that mediate sodium-driven transport of D-glucose. A cDNA, pRS1, encoding a membrane-associated protein that alters sugar transport by SGLT1, was cloned from pig kidney cortex.

Lambotte et al. (1996) cloned the intronless human homolog, termed RS1 by them, encoding a 617-amino acid protein with 74% amino acid identity to pRS1. By fluorescence in situ hybridization, the RS1 gene was localized to chromosome 1p36.1. Coexpression of hRS1 and SGLT1 from human intestine in oocytes showed that hRS1 protein inhibits sodium-D-glucose cotransporter expressed by human SGLT1 by decreasing both the V (max) and the apparent K(m) value of the transporter.