insulin-induced gene 2 protein (INSIG2)

Function

• mediates feedback control of cholesterol synthesis by controlling SCAP & HMGCR
• blocks processing of sterol regulatory element-binding proteins (SREBPs)
• retains SCAP-SREBF2 complex in the endoplasmic reticulum thus preventing it from escorting SREBPs to Golgi
• regulates ubiquitin-mediated proteasomal degradation of HMGCR
• binds to the SCAP-SREBF2 complex only in the presence of sterols

Structure

belongs to the INSIG family

Compartment

endoplasmic reticulum membrane

Expression

• does not require nuclear SREBPs for its expression
• when nuclear SREBP activity is low, is the only form of INSIG present in the celly

More general terms

• transmembrane 5 protein

Database

• OMIM: https://mirror.omim.org/entry/608660
• UniProt: http://www.uniprot.org/uniprot/Q9Y5U4.html