Zinc metalloprotease that mediates intramembrane proteolysis of proteins such as ATF6, ATF6B, SREBF1/SREBP1 and SREBF2/SREBP2 (PubMed:10805775, PubMed:11163209). Catalyzes the second step in the proteolytic activation of the sterol regulatory element-binding proteins (SREBPs) SREBF1/SREBP1 and SREBF2/SREBP2: cleaves SREBPs within the first transmembrane segment, thereby releasing the N-terminal segment with a portion of the transmembrane segment attached (PubMed:10805775, PubMed:27380894, PubMed

MembraneCytoplasmGolgi apparatus membrane

IFAP syndrome 1, with or without Bresheck syndrome

An X-linked syndrome characterized by a peculiar triad of follicular ichthyosis, total or subtotal atrichia, and photophobia of varying degree. Histopathologically, the epidermal granular layer is generally well-preserved or thickened at the infundibulum. Hair follicles are poorly developed and tend to be surrounded by an inflammatory infiltrate. A subgroup of patients is described with lamellar rather than follicular ichthyosis. Non-consistent features may include growth and psychomotor retardation, aganglionic megacolon, seizures and nail dystrophy.

Precursor of the transcription factor form (Processed sterol regulatory element-binding protein 1), which is embedded in the endoplasmic reticulum membrane (PubMed:32322062). Low sterol concentrations promote processing of this form, releasing the transcription factor form that translocates into the nucleus and activates transcription of genes involved in cholesterol biosynthesis and lipid homeostasis (By similarity) Key transcription factor that regulates expression of genes involved in cholest

Endoplasmic reticulum membraneGolgi apparatus membraneCytoplasmic vesicle, COPII-coated vesicle membraneNucleus

IFAP syndrome 2

An autosomal dominant form of IFAP syndrome, a disease characterized by a peculiar triad of follicular ichthyosis, total or subtotal atrichia, and photophobia of varying degree. IFAP2 patients manifest ichthyosis follicularis or follicular hyperkeratosis, hyperkeratotic plaques, sparse to no body hair, and photophobia with punctate corneal epithelial defects, corneal pannus, and complicated cataract. Ultrastructural hair analysis shows trichorrhexis nodosa.