ERLIN1

Erlin-1 is a protein encoded by the ERLIN1 gene in humans.
ERLIN1 and its homolog ERLIN2 are ER-localized members of the stomatin/prohibition/flotillin/HflKC family of proteins. They form a complex that functions to scaffold lipids and proteins.
ERLIN1 and ERLIN2 are predicted to assemble in a large ring-shaped hetero-oligomeric complex, likely formed by 24 subunits, similar to other members of the SPFH family.

Function

ERLIN1/2 are associated with cholesterol homeostasis. They interact with the SCAP–SREBP2–INSIG complex tightly under cholesterol repletion conditions, thus keeping this complex in the ER, where it is inactive. Silencing of ERLINs releases SREBP2 from the ER and allows it to travel to the Golgi, where it is processed and drives transcription of cholesterol synthesis genes. Activation of the SREBP2 pathway is as potent under ERLINs silencing as it is under cholesterol depletion conditions.