Abstract
We report the cloning of a gene, S2P, that encodes a putative metalloprotease required for intramembrane proteolysis of sterol-regulatory element-binding proteins (SREBPs) at Site-2. SREBPs are membrane-bound transcription factors that activate genes regulating cholesterol metabolism. The active NH2-terminal domains of SREBPs are released from membranes by sequential cleavage at two sites: Site-1, within the lumen of the endoplasmic reticulum; and Site-2, within a transmembrane segment. The human S2P gene was cloned by complementation of mutant CHO cells that cannot cleave SREBPs at Site-2 and are cholesterol auxotrophs. S2P defines a new family of polytopic membrane proteins that contain an HEXXH sequence characteristic of zinc metalloproteases. Mutation of the putative zinc-binding residues abolishes S2P activity. S2P encodes an unusual metalloprotease that cleaves proteins within transmembrane segments.
Publication types
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Research Support, Non-U.S. Gov't
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Research Support, U.S. Gov't, P.H.S.
MeSH terms
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Animals
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CCAAT-Enhancer-Binding Proteins*
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CHO Cells / enzymology
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Cloning, Molecular
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Cricetinae
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DNA Mutational Analysis
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DNA, Complementary
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DNA-Binding Proteins / metabolism*
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Endopeptidases / genetics*
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Endopeptidases / metabolism*
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Gene Expression Regulation, Enzymologic
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Genes, Reporter
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Genetic Complementation Test
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Humans
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Luciferases
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Membrane Proteins / genetics
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Membrane Proteins / metabolism
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Metalloendopeptidases / genetics
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Metalloendopeptidases / metabolism
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Molecular Sequence Data
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Mutation / physiology
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Nuclear Proteins / metabolism*
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Sequence Homology, Amino Acid
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Sterol Regulatory Element Binding Protein 1
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Transcription Factors*
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Transfection
Substances
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CCAAT-Enhancer-Binding Proteins
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DNA, Complementary
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DNA-Binding Proteins
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Membrane Proteins
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Nuclear Proteins
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SREBF1 protein, human
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Sterol Regulatory Element Binding Protein 1
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Transcription Factors
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Luciferases
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Endopeptidases
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Metalloendopeptidases
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SREBP site 2 protease
Associated data
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GENBANK/AF019611
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GENBANK/AF019612