Open AccessInsulin receptor substrate 1 is required for insulin-mediated mitogenic signal transduction.
Author(s) -
David W. Rose,
Alan R. Saltiel,
Mousumi Majumdar,
Stuart J. Decker,
Jerrold M. Olefsky
Publication year - 1994
Publication title -
proceedings of the national academy of sciences of the united states of america
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.011
H-Index - 771
eISSN - 1091-6490
pISSN - 0027-8424
DOI - 10.1073/pnas.91.2.797
Subject(s) - insulin receptor , insulin receptor substrate , insulin , biology , irs2 , irs1 , signal transduction , growth factor , grb10 , transfection , microbiology and biotechnology , tyrosine phosphorylation , bromodeoxyuridine , insulin like growth factor , receptor , cell growth , endocrinology , cell culture , biochemistry , insulin resistance , genetics
Insulin treatment of mammalian cells immediately stimulates the tyrosine phosphorylation of a cellular protein of 185 kDa referred to as pp185 or IRS-1 (insulin receptor substrate 1). The potential role of the IRS-1 protein in insulin signaling has been examined by microinjecting affinity-purified antibodies into living cells. Stably transfected Rat-1 fibroblasts, which overexpress the human insulin receptor, were microinjected and subsequently stimulated with insulin or other growth factors. Progression through the cell cycle was monitored by using a single-cell assay, which employs bromodeoxyuridine labeling of DNA and analysis with immunofluorescence microscopy. Microinjection of anti-IRS-1 antibody completely inhibited incorporation of bromodeoxyuridine into the nuclei of cells stimulated with insulin or insulin-like growth factor I but did not affect cells stimulated with serum or a variety of purified growth factors. These studies indicate that IRS-1 is a critical component of the insulin and insulin-like growth factor I signaling pathways, which lead to DNA synthesis and cell growth.