Abstract
Insulin receptor substrate-1 (IRS-1) plays a pivotal role in insulin signal transduction. It has been shown that the amino acids modulate insulin signaling at the level of IRS-1. Here we show that an amino acid unbalanced diet causes a reduction in serine phosphorylation as well as an elevation in insulin-induced tyrosine phosphorylation of IRS-1 in rat muscle. In fibroblasts and myotube cells, the effect of amino acid deprivation on IRS-1 phosphorylation was evident only when cells were pretreated with reagents causing hyperphosphorylation of serines of IRS-1. But, the target kinases of these reagents were not inactivated by amino acid deprivation, suggesting that amino acid deprivation activates serine/threonine phosphatase(s) of IRS-1. The phosphatases regulated by mammalian target of rapamycin do not appear to participate in the dephosphorylation either. These results suggest that amino acid deprivation dephosphorylates IRS-1 through unidentified serine/threonine phosphatases and thereby potentiates insulin signaling.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
