Recombinant Human SREBP1 protein (GST tag N-Terminus)

Specifications

Form

Liquid

General info

Function

Sterol regulatory element-binding protein 1. 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).. Processed sterol regulatory element-binding protein 1. Key transcription factor that regulates expression of genes involved in cholesterol biosynthesis and lipid homeostasis (PubMed : 12177166, PubMed : 32322062, PubMed : 8402897). Binds to the sterol regulatory element 1 (SRE-1) (5'-ATCACCCCAC-3'). Has dual sequence specificity binding to both an E-box motif (5'-ATCACGTGA-3') and to SRE-1 (5'-ATCACCCCAC-3') (PubMed : 12177166, PubMed : 8402897). Regulates the promoters of genes involved in cholesterol biosynthesis and the LDL receptor (LDLR) pathway of sterol regulation (PubMed : 12177166, PubMed : 32322062, PubMed : 8402897).. Isoform SREBP-1A. Isoform expressed only in select tissues, which has higher transcriptional activity compared to SREBP-1C (By similarity). Able to stimulate both lipogenic and cholesterogenic gene expression (PubMed : 12177166, PubMed : 32497488). Has a role in the nutritional regulation of fatty acids and triglycerides in lipogenic organs such as the liver (By similarity). Required for innate immune response in macrophages by regulating lipid metabolism (By similarity).. Isoform SREBP-1C. Predominant isoform expressed in most tissues, which has weaker transcriptional activity compared to isoform SREBP-1A (By similarity). Primarily controls expression of lipogenic gene (PubMed : 12177166). Strongly activates global lipid synthesis in rapidly growing cells (By similarity).. Isoform SREBP-1aDelta. The absence of Golgi proteolytic processing requirement makes this isoform constitutively active in transactivation of lipogenic gene promoters.. Isoform SREBP-1cDelta. The absence of Golgi proteolytic processing requirement makes this isoform constitutively active in transactivation of lipogenic gene promoters.

Sequence similarities

Belongs to the SREBP family.

Post-translational modifications

Sterol regulatory element-binding protein 1. Processed in the Golgi apparatus, releasing the protein from the membrane (PubMed:32322062, PubMed:8626610). At low cholesterol the SCAP-SREBP complex is recruited into COPII vesicles for export from the endoplasmic reticulum (PubMed:32322062, PubMed:8626610). In the Golgi, complex SREBPs are cleaved sequentially by site-1 (MBTPS1, S1P) and site-2 (MBTPS2, S2P) protease (PubMed:32322062, PubMed:8626610). The first cleavage by site-1 protease occurs within the luminal loop, the second cleavage by site-2 protease occurs within the first transmembrane domain, releasing the transcription factor from the Golgi membrane (PubMed:32322062).. Phosphorylated by AMPK, leading to suppress protein processing and nuclear translocation, and repress target gene expression (By similarity). Phosphorylation at Ser-402 by SIK1 represses activity possibly by inhibiting DNA-binding (By similarity).. Processed sterol regulatory element-binding protein 1. Ubiquitinated; the nuclear form has a rapid turnover and is rapidly ubiquitinated and degraded by the proteasome in the nucleus.

Subcellular localisation

Nucleus