Format

Send to

Choose Destination
See comment in PubMed Commons below
Biochem Biophys Res Commun. 1994 Jul 29;202(2):1038-46.

cDNA cloning of the rat IGF I receptors: structural analysis of rat and human IGF I and insulin receptors reveals differences in alternative splicing and receptor-specific domain conservation.

Author information

1
Research Division, Joslin Diabetes Center, Harvard Medical School, Boston, Massachusetts 02215.

Abstract

IGF I and insulin receptors are homologous proteins that function in distinct physiological pathways. To define domains that might contribute to differences between IGF I and insulin receptors, we cloned the rat IGF I receptor cDNA and performed a comparative sequence analysis of specific functional domains in the two receptor types of rats and humans. Since alternative splicing has been shown to alter the activities of both IGF I and insulin receptors, we also examined the mRNA splicing patterns of the two receptors. The C-terminal region exhibits the lowest degree of amino acid homology between rat and human IGF I receptors (85%) and the tyrosine kinase domain the highest homology (98%). In the region corresponding to the CAG+/-alternative splicing site of the human IGF I receptor, a nucleotide change in the rat eliminates the alternative acceptor splice site. The rat IGF I receptor has no equivalent to the alternatively spliced exon 11 of the insulin receptor. The IGF I and insulin receptors are highly homologous in the tyrosine kinase domain (84%), but differ markedly in other specific regions (e.g., 22-26% homology in the transmembrane domain, 45% homology in the C-terminal domain). We speculate that these regions of divergent sequence may have roles in determining distinct signaling properties of IGF I and insulin receptors.

PMID:
8048916
[Indexed for MEDLINE]
PubMed Commons home

PubMed Commons

0 comments
How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for Elsevier Science
    Loading ...
    Support Center