Sterol resistance in CHO cells traced to point mutation in SREBP cleavage-activating protein.
Through expression cloning we have isolated a cDNA-encoding SREBP cleavage-activating protein (SCAP), which regulates cholesterol metabolism by stimulating cleavage of transcription factors SREBP-1 and -2, thereby releasing them from membranes. The cDNA was isolated from Chinese hamster ovary cells with a dominant mutation that renders them resistant to sterol-mediated suppression of cholesterol synthesis and uptake. Sterol resistance was traced to a G-->A transition at codon 443 of SCAP, changing aspartic acid to asparagine. The D443N mutation enhances the cleavage-stimulating ability of SCAP and renders it resistant to inhibition by sterols. SCAP has multiple membrane-spanning regions, five of which resemble the sterol-sensing domain of HMG CoA reductase, an endoplasmic reticulum enzyme whose degradation is accelerated by sterols. SCAP appears to be a central regulator of cholesterol metabolism in animal cells.
Department of Molecular Genetics, University of Texas Southwestern Medical Center, Dallas 75235, USA.
X
X
Hua
A
A
Nohturfft
J L
JL
Goldstein
M S
MS
Brown
D000595:Amino Acid Sequence; D000818:Animals; D022762:CCAAT-Enhancer-Binding Proteins; D016466:CHO Cells / Q000187:drug effects / Q000378:metabolism*; D017173:Caenorhabditis elegans / Q000235:genetics; D002784:Cholesterol / Q000378:metabolism*; D003001:Cloning, Molecular; D006224:Cricetinae; D003412:Cricetulus; D018076:DNA, Complementary / Q000235:genetics; D004268:DNA-Binding Proteins / Q000378:metabolism*; D005246:Feedback; D005786:Gene Expression Regulation; D005796:Genes; D017930:Genes, Reporter; D006801:Humans; D006903:Hydroxymethylglutaryl CoA Reductases / Q000737:chemistry; D047908:Intracellular Signaling Peptides and Proteins; D008565:Membrane Proteins / Q000235:genetics / Q000502:physiology*; D008969:Molecular Sequence Data; D009687:Nuclear Proteins / Q000378:metabolism*; D011973:Receptors, LDL / Q000096:biosynthesis* / Q000235:genetics; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D013045:Species Specificity; D051780:Sterol Regulatory Element Binding Protein 1; D051782:Sterol Regulatory Element Binding Protein 2; D013261:Sterols / Q000494:pharmacology*; D014157:Transcription Factors / Q000378:metabolism; D014162:Transfection
D022762:CCAAT-Enhancer-Binding Proteins; D018076:DNA, Complementary; D004268:DNA-Binding Proteins; D047908:Intracellular Signaling Peptides and Proteins; D008565:Membrane Proteins; D009687:Nuclear Proteins; D011973:Receptors, LDL; C497387:SREBF1 protein, human; C497390:SREBF2 protein, human; C102196:SREBP cleavage-activating protein; D051780:Sterol Regulatory Element Binding Protein 1; D051782:Sterol Regulatory Element Binding Protein 2; D013261:Sterols; D014157:Transcription Factors; D002784:Cholesterol; D006903:Hydroxymethylglutaryl CoA Reductases