Cloning and expression of a cDNA encoding human sterol carrier protein 2.

TitleCloning and expression of a cDNA encoding human sterol carrier protein 2.
Publication TypeJournal Article
Year of Publication1991
AuthorsYamamoto R, Kallen CB, Babalola GO, Rennert H, Billheimer JT, Strauss JF
JournalProc Natl Acad Sci U S A
Date Published1991 Jan 15
KeywordsAmino Acid Sequence, Animals, Base Sequence, Blotting, Northern, Carrier Proteins, Cell Line, Cloning, Molecular, DNA, Gene Library, Genetic Vectors, Humans, Liver, Molecular Sequence Data, Molecular Weight, Plant Proteins, Poly A, Recombinant Proteins, RNA, RNA, Messenger, Steroids, Sterols, Transfection

We report the cloning and expression of a cDNA encoding human sterol carrier protein 2 (SCP2). The 1.3-kilobase (kb) cDNA contains an open reading frame which encompasses a 143-amino acid sequence which is 89% identical to the rat SCP2 amino acid sequence. The deduced amino acid sequence of the polypeptide reveals a 20-residue amino-terminal leader sequence in front of the mature polypeptide, which contains a carboxyl-terminal tripeptide (Ala-Lys-Leu) related to the peroxisome targeting sequence. The expressed cDNA in COS-7 cells yields a 15.3-kDa polypeptide and increased amounts of a 13.2-kDa polypeptide, both reacting with a specific rabbit antiserum to rat liver SCP2. The cDNA insert hybridizes with 3.2- and 1.8-kb mRNA species in human liver poly(A)+ RNA. In human fibroblasts and placenta the 1.8-kb mRNA was most abundant. Southern blot analysis suggests either that there are multiple copies of the SCP2 gene in the human genome or that the SCP2 gene is very large. Coexpression of the SCP2 cDNA with expression vectors for cholesterol side-chain cleavage enzyme and adrenodoxin resulted in a 2.5-fold enhancement of progestin synthesis over that obtained with expression of the steroidogenic enzyme system alone. These findings are concordant with the notion that SCP2 plays a role in regulating steroidogenesis, among other possible functions.

Alternate JournalProc Natl Acad Sci U S A
PubMed ID1703300
PubMed Central IDPMC50831
Grant ListHD-06274 / HD / NICHD NIH HHS / United States
Related Faculty: 
Hanna Rennert, Ph.D.

Pathology & Laboratory Medicine 1300 York Avenue New York, NY 10065 Phone: (212) 746-6464
Surgical Pathology: (212) 746-2700