Molecular cloning of rat insulin-like growth factor I complementary deoxyribonucleic acids: differential messenger ribonucleic acid processing and regulation by growth hormone in extrahepatic tissues.
Two classes of insulin-like growth factor I (IGF-I) cDNAs were isolated from an adult rat liver library using a human IGF-I cDNA probe. The two types of rat IGF-I cDNA differed by the presence or absence of a 52-base pair insert which altered the derived C-terminal amino acid sequence of the E peptide, but not the 3'-untranslated region or the sequence coding for the mature IGF-I protein. When probes derived from these cDNA clones were hybridized to Northern blots of rat mRNA, specific bands of 8.6, 2.1, and 1.0-1.4 kilobases were seen. Hybridization to poly(A)+ RNA from various tissues from GH-treated and control rats demonstrated an increase in IGF-I mRNA due to GH treatment in all tissues examined.
Roberts
C T
CT
Diabetes Branch, National Institute of Diabetes, Digestive and Kidney Diseases, Bethesda, Maryland 20892.
Lasky
S R
SR
Lowe
W L
WL
Seaman
W T
WT
LeRoith
D
D
D000818:Animals; D001483:Base Sequence; D003001:Cloning, Molecular / Q000379:methods; D004247:DNA / Q000235:genetics* / Q000302:isolation & purification; D013006:Growth Hormone / Q000494:pharmacology*; D007334:Insulin-Like Growth Factor I / Q000235:genetics* / Q000302:isolation & purification; D008099:Liver / Q000032:analysis / Q000378:metabolism*; D008297:Male; D008969:Molecular Sequence Data; D012333:RNA, Messenger / Q000187:drug effects* / Q000235:genetics; D051381:Rats; D011919:Rats, Inbred Strains; D013002:Somatomedins / Q000235:genetics*; D014158:Transcription, Genetic
D012333:RNA, Messenger; D013002:Somatomedins; D007334:Insulin-Like Growth Factor I; D013006:Growth Hormone; D004247:DNA