| First Author | Brodbeck D | Year | 2001 |
| Journal | J Biol Chem | Volume | 276 |
| Issue | 31 | Pages | 29550-8 |
| PubMed ID | 11387345 | Mgi Jnum | J:70720 |
| Mgi Id | MGI:2138040 | Doi | 10.1074/jbc.M104633200 |
| Citation | Brodbeck D, et al. (2001) Two Splice Variants of Protein Kinase Bgamma Have Different Regulatory Capacity Depending on the Presence or Absence of the Regulatory Phosphorylation Site Serine 472 in the Carboxyl-terminal Hydrophobic Domain. J Biol Chem 276(31):29550-8 |
| abstractText | We have reported previously the cloning and characterization of human and mouse protein kinase Bgamma (PKBgamma), the third member of the PKB family of second messenger-regulated serine/threonine kinases (Brodbeck, D., Cron, P., and Hemmings, B. A. (1999) J. Biol. Chem. 274, 9133-9136). Here we report the isolation of human and mouse PKBgamma1, a splice variant lacking the second regulatory phosphorylation site Ser-472 in the hydrophobic C-terminal domain. Expression of PKBgamma1 is low compared with PKBgamma, and it is regulated in different human tissues. We show that PKBgamma and PKBgamma1 differ in their response to stimulation by insulin, pervanadate, peroxide, or okadaic acid. Activation of PKBgamma1 requires phosphorylation at a single regulatory site Thr-305. Interestingly, this site is phosphorylated to a higher extent in PKBgamma compared with PKBgamma1 upon maximal stimulation by pervanadate, and this is reflected in the respective specific kinase activities. Furthermore, upon insulin stimulation of transfected cells, PKBgamma1 translocates to the plasma membrane to a lesser extent than PKBgamma. Taken together, these results suggest that phosphorylation of the hydrophobic motif at the extreme C terminus of PKBgamma may facilitate translocation of the kinase to the membrane and/or its phosphorylation on the activation loop site by phosphoinositide-dependent protein kinase-1. |
