First Author | Carlson CJ | Year | 2004 |
Journal | Biochem Biophys Res Commun | Volume | 316 |
Issue | 2 | Pages | 533-9 |
PubMed ID | 15020250 | Mgi Jnum | J:88847 |
Mgi Id | MGI:3037344 | Doi | 10.1016/j.bbrc.2004.02.082 |
Citation | Carlson CJ, et al. (2004) Mammalian target of rapamycin regulates IRS-1 serine 307 phosphorylation. Biochem Biophys Res Commun 316(2):533-9 |
abstractText | Insulin signaling can be negatively regulated by phosphorylation of serine 307 of the insulin receptor substrate (IRS)-1. Rapamycin, an inhibitor of the kinase mTOR, can prevent serine 307 phosphorylation and the development of insulin resistance. We further investigated the role of mTOR in regulating serine 307 phosphorylation, demonstrating that serine 307 phosphorylation in response to insulin, anisomycin, or tumor necrosis factor was quantitatively and temporally associated with activation of mTOR and could be inhibited by rapamycin. Amino acid stimulation activated mTOR and resulted in IRS-1 serine 307 phosphorylation without activating PKB or JNK. Okadaic acid, an inhibitor of the phosphatase PP2A, activated mTOR and stimulated the phosphorylation of serine 307 in a rapamycin-sensitive manner, indicating serine 307 phosphorylation requires mTOR activity but not PP2A, suggesting that mTOR itself may be responsible for phosphorylating serine 307. Finally, we demonstrated that serine 307 phosphorylated IRS-1 is detected primarily in the cytosolic fraction. |