This region is found at the N-terminus of the TRC8 protein Swiss:Q8WU17. TRC8 is an E3 ubiquitin-protein ligase also known as RNF139. This region contains 12 transmembrane domains. This region has been suggested to contain a sterol sensing domain [1]. It has been found that TRC8 protein levels are sterol responsive and that it binds and stimulates ubiquitylation of the endoplasmic reticulum anchor protein INSIG [2].

1: The hereditary renal cell carcinoma 3;8 translocation fuses FHIT to a patched-related gene, TRC8. Gemmill RM, West JD, Boldog F, Tanaka N, Robinson LJ, Smith DI, Li F, Drabkin HA; Proc Natl Acad Sci U S A. 1998;95:9572-9577. PMID:9689122

2: The TRC8 ubiquitin ligase is sterol regulated and interacts with lipid and protein biosynthetic pathways. Lee JP, Brauweiler A, Rudolph M, Hooper JE, Drabkin HA, Gemmill RM; Mol Cancer Res. 2010;8:93-106. PMID:20068067