Nature and regulation of the receptors for insulin-like growth factors

Journal Article · Tue Jan 01 04:00:00 EST 1985 · Annu. Rev. Physiol.; (United States)

DOI:https://doi.org/10.1146/annurev.ph.47.030185.002233· OSTI ID:5219379

Rechler, M M; Nissley, S P

Two subtypes of IGF receptors have been identified. Type I IGF receptors have a Mr greater than 300,000 and are composed of disulfide-linked 130,000-dalton (alpha) and approximately 90,000-dalton (beta) subunits. Type I receptors preferentially bind IGF-I but also bind IGF-II and, more weakly, insulin. Type II IGF receptors consist of a 250,000-dalton protein that contains internal disulfide bonds but is not linked to other membrane components. Type II receptors bind IGF-II with higher affinity than IGF-I. They do not interact with even very high concentrations of insulin. Type I IGF receptors and insulin receptors are homologous structures. Type II IGF receptors do not appear to be homologous to type I receptors. Type II receptors do not appear to be downregulated. Insulin acutely upregulates type II IGF receptors in intact rat adipose cells by effecting a redistribution of receptors cycling between a large intracellular pool and the plasma membrane. Insulin and the IGFs elicit the same biological responses, either by cross-reacting with one of the receptors for the heterologous ligand or by concurrent activation of convergent effector pathways by binding to the homologous receptor. Which mechanism is utilized appears to depend more on the tissue than on the biological response. Insulin desensitizes rat hepatoma cells to the actions of insulin and IGFs, mediated by both insulin and IGF receptors, by mechanisms distal to hormone binding and possibly common to IGF and insulin effector pathways.

• Research Organization: National Institute of Arthritis, Bethesda, MD
• OSTI ID: 5219379
• Journal Information: Annu. Rev. Physiol.; (United States), Journal Name: Annu. Rev. Physiol.; (United States); ISSN ARPHA
• Country of Publication: United States
• Language: English

Related Subjects

550601* -- Medicine-- Unsealed Radionuclides in Diagnostics
62 RADIOLOGY AND NUCLEAR MEDICINE
AMINO ACIDS
ANIMAL CELLS
CARBOXYLIC ACIDS
CHEMICAL REACTIONS
CONNECTIVE TISSUE CELLS
ENZYME ACTIVITY
ENZYMES
FAT CELLS
GROWTH
HORMONES
HYDROXY ACIDS
INSULIN
IODINE ISOTOPES
ISOTOPE APPLICATIONS
ISOTOPES
MOLECULAR BIOLOGY
MOLECULAR WEIGHT
ORGANIC ACIDS
ORGANIC COMPOUNDS
PEPTIDE HORMONES
PEPTIDES
PHOSPHORUS-GROUP TRANSFERASES
PHOSPHORYLATION
PHOSPHOTRANSFERASES
PROTEINS
RADIORECEPTOR ASSAY
RECEPTORS
SOMATIC CELLS
TRACER TECHNIQUES
TRANSFERASES
TUMOR CELLS
TYROSINE