Signal Sequence Receptor Gamma (SSRg)

The signal sequence receptor (SSR) is a glycosylated endoplasmic reticulum (ER) membrane receptor associated with protein translocation across the ER membrane. SSR is either not required for translocation or is one of a family of functionally redundant components. The SSR is comprised of four membrane proteins/subunits: alpha, beta, gamma, and delta. The first two are glycosylated subunits and the latter two are non-glycosylated subunits.Signal Sequence Receptor Gamma is the gamma subunit and is predicted to span the membrane four times. The deduced 185-amino acid protein spans the membrane 4 times and is expressed as a 20-kD protein. Ssr3 was associated in equal amounts with Ssr1, Ssr2, and Ssr4 in pancreatic microsomes.