Insulin rapidly stimulates tyrosine kinase activity of its receptor resulting in phosphorylation of its cytosolic substrate insulin receptor substrate 1 (IRS-1), which in turn associates with and activates the enzyme phosphatidylinositol 3-kinase (PI 3-kinase). In the present study we have examined these three initial steps in insulin action during the differentiation of 3T3-F442A adipocytes an...

OBJECTIVE Phogrin and IA-2, autoantigens in insulin-dependent diabetes, have been shown to be involved in insulin secretion in pancreatic beta-cells; however, implications at a molecular level are confusing from experiment to experiment. We analyzed biological functions of phogrin in beta-cells by an RNA interference technique. RESEARCH DESIGN AND METHODS Adenovirus-mediated expression of sho...

The mammalian target of rapamycin (mTOR) integrates signals from nutrients and insulin via two distinct complexes, mTORC1 and mTORC2. Disruption of mTORC2 impairs the insulin-induced activation of Akt, an mTORC2 substrate. Here, we found that mTORC2 can also regulate insulin signaling at the level of insulin receptor substrate-1 (IRS-1). Despite phosphorylation at the mTORC1-mediated serine sit...

Insulin receptor substrate (IRS) is a key adapter protein mediating effects of insulin and insulin-like growth factors (IGF) in cells. IRS-1 member the family, which associated with tumor initiation progression. The aim study to determine level blood patients (n = 81) diabetes mellitus COVID-19. was determined enzyme-linked immunosorbent assay (ELISA) (Elabscience, USA). measurements were perfo...

Insulin receptor substrate-1 (IRS-1), a substrate of various receptor tyrosine kinases transmits mitogenic signals initiated by extracellular ligands. This protein is involved in normal hepatocyte growth and has been found to be overexpressed in human hepatocellular carcinoma. Expression of a carboxy-terminal truncated IRS-1 molecule containing the pleckstrin homology and phosphotyrosine-bindin...

BACKGROUND Protein-tyrosine phosphatase 1B (PTP1B) is a physiological regulator of insulin signaling and energy balance, but its role in brown fat adipogenesis requires additional investigation. METHODOLOGY/PRINCIPAL FINDINGS To precisely determine the role of PTP1B in adipogenesis, we established preadipocyte cell lines from wild type and PTP1B knockout (KO) mice. In addition, we reconstitut...

Insulin binding to its receptor stimulates a tyrosine-specific protein kinase. This enzyme phosphorylates the insulin receptor, as well as a variety of exogenous substrates in vitro. In the present studies, we have identified an endogenous substrate for the insulin receptor-associated kinase. We studied insulin-stimulated protein phosphorylation in partially purified insulin receptor preparatio...