Abstract

The insulin-like growth factor II (IGF-II) receptor has high affinity binding sites for the polypeptide IGF-II and glycosylated lysosomal enzymes. This unique receptor's key role in transporting lysosomal enzymes is well established, but the mechanism by which IGF-II-initiated signal transduction events are mediated by the IGF-II receptor is controversial. To help elucidate this mechanism, the objective of this project is to map the ICF-II binding site of the IGF-II receptor using two complementary approaches. First, purified 125I-IGF-II affinity-labelled receptors will be digested with endoproteinase Glu-C, then peptide regions of the receptor covalently attached to IGF-II will be isolated for sequencing. Second, cDNA clones encoding the IGF-II receptor's avian homolog, which does not bind ICF-II, will be isolated by screening chicken cDNA libraries with radiolabelled fragments of mammalian IGF-II receptor cDNAs. Sequence and mapping information as well as reagents obtained in those studies will be used to designate targets for site-directed mutagenesis of the mammalian receptor's IGF-II binding site and to design avian/mammalian receptor chimeras. Wild-type, mutant and chimeric receptors will be expressed in mammalian cells to assess IGF-II binding parameters, and to investigate structure-function relationships linking IGF-II binding to signal transduction.

  Funding Agency

Agency
National Institute of Health (NIH)
Institute
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
Type
Research Project (R01)
Project #
5R01DK044212-02
Application #
2143616
Study Section
Cellular Biology and Physiology Subcommittee 1 (CBY)
Project Start
1994-01-01
Project End
1996-12-31
Budget Start
1995-01-01
Budget End
1995-12-31
Support Year
2
Fiscal Year
1995
Total Cost
Indirect Cost

  Institution

Name
University of Nebraska Medical Center
Department
Biochemistry
Type
Schools of Medicine
DUNS #
City
Omaha
State
NE
Country
United States
Zip Code
68198

  Publications

Schaffer, Beverly S; Lin, Ming-Fong; Byrd, James C et al. (2003) Opposing roles for the insulin-like growth factor (IGF)-II and mannose 6-phosphate (Man-6-P) binding activities of the IGF-II/Man-6-P receptor in the growth of prostate cancer cells. Endocrinology 144:955-66
Byrd, J C; Park, J H; Schaffer, B S et al. (2000) Dimerization of the insulin-like growth factor II/mannose 6-phosphate receptor. J Biol Chem 275:18647-56
Byrd, J C; MacDonald, R G (2000) Mechanisms for high affinity mannose 6-phosphate ligand binding to the insulin-like growth factor II/mannose 6-phosphate receptor. J Biol Chem 275:18638-46
Byrd, J C; Devi, G R; de Souza, A T et al. (1999) Disruption of ligand binding to the insulin-like growth factor II/mannose 6-phosphate receptor by cancer-associated missense mutations. J Biol Chem 274:24408-16
Devi, G R; De Souza, A T; Byrd, J C et al. (1999) Altered ligand binding by insulin-like growth factor II/mannose 6-phosphate receptors bearing missense mutations in human cancers. Cancer Res 59:4314-9
Devi, G R; Byrd, J C; Slentz, D H et al. (1998) An insulin-like growth factor II (IGF-II) affinity-enhancing domain localized within extracytoplasmic repeat 13 of the IGF-II/mannose 6-phosphate receptor. Mol Endocrinol 12:1661-72
Garmroudi, F; Devi, G; Slentz, D H et al. (1996) Truncated forms of the insulin-like growth factor II (IGF-II)/mannose 6-phosphate receptor encompassing the IGF-II binding site: characterization of a point mutation that abolishes IGF-II binding. Mol Endocrinol 10:642-51
Garmroudi, F; MacDonald, R G (1994) Localization of the insulin-like growth factor II (IGF-II) binding/cross-linking site of the IGF-II/mannose 6-phosphate receptor to extracellular repeats 10-11. J Biol Chem 269:26944-52