Nature and regulation of the insulin receptor: structure and function

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

DOI:https://doi.org/10.1146/annurev.ph.47.030185.002041· OSTI ID:5150237

Czech, M P

Native, cell-surface insulin receptor consists of two glycoprotein subunit types with apparent masses of about 125,000 daltons (alpha subunit) and 90,000 daltons (beta subunit). The alpha and beta insulin-receptor subunits seem to have distinct functions such that alpha appears to bind hormone whereas beta appears to possess intrinsic tyrosine kinase activity. In detergent extracts, insulin activates receptor autophosphorylation of tyrosine residues on its beta subunit, whereas in the presence of reductant, the alpha subunit is also phosphorylated. In intact cells, insulin activates serine/threonine phosphorylation of insulin receptor beta subunit as well as tyrosine phosphorylation. The biological role of the receptor-associated tyrosine kinase is not known. The insulin receptor kinase is regulated by beta-adrenergic agonists and other agents that elevate cAMP in adipocytes, presumably via the cAMP-dependent protein kinase. Such agents decrease receptor affinity for insulin and partially uncouple receptor tyrosine kinase activity from activation by insulin. These effects appear to contribute to the biological antagonism between insulin and beta-agonists. These data suggest the hypothesis that a complex network of tyrosine and serine/threonine phosphorylations on the insulin receptor modulate its binding and kinase activities in an antagonistic manner.

• Research Organization: Univ. of Massachusetts Medical Center, Worcester
• OSTI ID: 5150237
• 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 ACID SEQUENCE
AMINO ACIDS
ANTIBODIES
CARBOXYLIC ACIDS
CHEMICAL REACTIONS
ENZYME ACTIVITY
ENZYMES
HORMONES
HYDROXY ACIDS
INSULIN
IODINE ISOTOPES
ISOTOPE APPLICATIONS
ISOTOPES
KINETICS
MOLECULAR STRUCTURE
MONOCLONAL ANTIBODIES
ORGANIC ACIDS
ORGANIC COMPOUNDS
PEPTIDE HORMONES
PHOSPHORUS-GROUP TRANSFERASES
PHOSPHORYLATION
PHOSPHOTRANSFERASES
RADIORECEPTOR ASSAY
RECEPTORS
TRACER TECHNIQUES
TRANSFERASES
TYROSINE