LMPD Database

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LMP001852

UniProt Annotations

Entry Information
Gene Namesterol regulatory element binding transcription factor 1
Protein EntrySRBP1_HUMAN
UniProt IDP36956
SpeciesHuman
Comments
Comment typeDescription
Alternative ProductsEvent=Alternative splicing; Named isoforms=6; Comment=Additional isoforms seem to exist.; Name=SREBP-1A; IsoId=P36956-1; Sequence=Displayed; Name=SREBP-1B; IsoId=P36956-2; Sequence=VSP_002150; Name=SREBP-1C; IsoId=P36956-3; Sequence=VSP_002149, VSP_002150; Note=Predominantly expressed in liver and adipose tissues.; Name=4; IsoId=P36956-4; Sequence=VSP_030859; Note=No experimental confirmation available.; Name=SREBP-1aDelta; IsoId=P36956-5; Sequence=VSP_047598, VSP_047599; Note=The absence of Golgi proteolytic processing requirement makes this isoform constitutively active in transactivation of lipogenic gene promoters.; Name=SREBP-1cDelta; IsoId=P36956-6; Sequence=VSP_002149, VSP_047598, VSP_047599; Note=The absence of Golgi proteolytic processing requirement makes this isoform constitutively active in transactivation of lipogenic gene promoters.;
FunctionTranscriptional activator required for lipid homeostasis. Regulates transcription of the LDL receptor gene as well as the fatty acid and to a lesser degree the cholesterol synthesis pathway (By similarity). 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').
InteractionP45481:Crebbp (xeno); NbExp=2; IntAct=EBI-948328, EBI-296306; Q96RN5:MED15; NbExp=6; IntAct=EBI-948328, EBI-394506; Q96EB6:SIRT1; NbExp=2; IntAct=EBI-948338, EBI-1802965;
PtmAt low cholesterol the SCAP/SREBP complex is recruited into COPII vesicles for export from the ER. In the Golgi complex SREBPs are cleaved sequentially by site-1 and site-2 protease. 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 and releases the transcription factor from the Golgi membrane. Apoptosis triggers cleavage by the cysteine proteases caspase-3 and caspase-7.
PtmPhosphorylated by AMPK, leading to suppress protein processing and nuclear translocation, and repress target gene expression. Phosphorylation at Ser-402 by SIK1 represses activity possibly by inhibiting DNA-binding (By similarity).
Sequence CautionSequence=AAB28522.2; Type=Erroneous initiation; Note=Translation N-terminally extended.; Evidence= ; Sequence=BAD92846.1; Type=Miscellaneous discrepancy; Note=Intron retention.; Evidence= ;
SimilarityBelongs to the SREBP family.
SimilarityContains 1 bHLH (basic helix-loop-helix) domain.
Subcellular LocationEndoplasmic reticulum membrane; Multi-pass membrane protein. Golgi apparatus membrane; Multi-pass membrane protein. Cytoplasmic vesicle, COPII-coated vesicle membrane; Multi-pass membrane protein. Note=Moves from the endoplasmic reticulum to the Golgi in the absence of sterols.
Subcellular LocationIsoform SREBP-1aDelta: Nucleus {ECO
Subcellular LocationIsoform SREBP-1cDelta: Nucleus {ECO
Subcellular LocationProcessed sterol regulatory element-binding protein 1: Nucleus.
SubunitForms a tight complex with SCAP in the ER membrane. Efficient DNA binding of the soluble transcription factor fragment requires dimerization with another bHLH protein. Interacts with LMNA.
Tissue SpecificityExpressed in a wide variety of tissues, most abundant in liver and adrenal gland. In fetal tissues lung and liver shows highest expression. Isoform SREBP-1C predominates in liver, adrenal gland and ovary, whereas isoform SREBP-1A predominates in hepatoma cell lines. Isoform SREBP-1A and isoform SREBP-1C are found in kidney, brain, white fat, and muscle.
Web ResourceName=Wikipedia; Note=Sterol regulatory element- binding protein entry; URL="http://en.wikipedia.org/wiki/Sterol_regulatory_element_binding_protein";