| First Author | Yip MF | Year | 2008 |
| Journal | Cell Metab | Volume | 8 |
| Issue | 5 | Pages | 384-98 |
| PubMed ID | 19046570 | Mgi Jnum | J:143750 |
| Mgi Id | MGI:3828899 | Doi | 10.1016/j.cmet.2008.09.011 |
| Citation | Yip MF, et al. (2008) CaMKII-mediated phosphorylation of the myosin motor Myo1c is required for insulin-stimulated GLUT4 translocation in adipocytes. Cell Metab 8(5):384-98 |
| abstractText | The unconventional myosin Myo1c has been implicated in insulin-regulated GLUT4 translocation to the plasma membrane in adipocytes. We show that Myo1c undergoes insulin-dependent phosphorylation at S701. Phosphorylation was accompanied by enhanced 14-3-3 binding and reduced calmodulin binding. Recombinant CaMKII phosphorylated Myo1c in vitro and siRNA knockdown of CaMKIIdelta abolished insulin-dependent Myo1c phosphorylation in vivo. CaMKII activity was increased upon insulin treatment and the CaMKII inhibitors CN21 and KN-62 or the Ca(2+) chelator BAPTA-AM blocked insulin-dependent Myo1c phosphorylation and insulin-stimulated glucose transport in adipocytes. Myo1c ATPase activity was increased after CaMKII phosphorylation in vitro and after insulin stimulation of CHO/IR/IRS-1 cells. Expression of wild-type Myo1c, but not S701A or ATPase dead mutant K111A, rescued the inhibition of GLUT4 translocation by siRNA-mediated Myo1c knockdown. These data suggest that insulin regulates Myo1c function via CaMKII-dependent phosphorylation, and these events play a role in insulin-regulated GLUT4 trafficking in adipocytes likely involving Myo1c motor activity. |
