Cloning and characterization of the growth hormone-dependent insulin-like growth factor binding protein (IGFBP-3) in the rat.
We report for the first time the complete amino acid sequence for the growth hormone dependent insulin-like growth factor binding protein (IGFBP-3) in the rat. A human IGFBP-3 clone was generated using the polymerase chain reaction (PCR) and used to screen a rat liver cDNA library. cDNA clones of the rat IGFBP-3 were isolated and the full amino acid sequence deduced. The sequence begins with a putative, 26 amino acid signal peptide followed by a 265 amino acid binding protein. The amino acid sequence is over 80% homologous with the equivalent human IGFBP-3 form and shows complete conservation of 18 cysteine residues that are clustered at the amino and carboxy ends of the protein. IGFBP-3 is the binding subunit of the major circulating IGFBP in the rat, and hence the availability of precise structural data and cDNA probes provides an important opportunity for a detailed study of the control of IGFBP-3 synthesis at the level of gene expression.
Prince Henry's Institute of Medical Research, Prince Henry's Hospital Campus, Monash Medical Centre, Melbourne, Australia.
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Albiston
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Herington
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D015152:Blotting, Northern; D015139:Blotting, Southern; D002352:Carrier Proteins / Q000235:genetics*; D003001:Cloning, Molecular; D004247:DNA / Q000235:genetics; D018969:Insulin-Like Growth Factor Binding Proteins; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction; D012333:RNA, Messenger / Q000235:genetics; D051381:Rats; D013002:Somatomedins / Q000378:metabolism*
D002352:Carrier Proteins; D018969:Insulin-Like Growth Factor Binding Proteins; D012333:RNA, Messenger; D013002:Somatomedins; D004247:DNA