The SREBP pathway. SREBP resides in the endoplasmic reticulum (ER), where it is bound to SCAP by its regulatory (Reg) domain. When cholesterol levels fall, SCAP and SREBP move to the Golgi complex, where SREBP undergoes successive proteolytic cleavages by a serine protease and a metalloprotease. The released DNA-binding domain moves to the nucleus to alter gene expression.

[Information from an illustration provided by Dr. Michael Brown and Dr. Joseph Goldstein.]