| First Author | Dong LQ | Year | 2002 |
| Journal | Biochem Biophys Res Commun | Volume | 294 |
| Issue | 1 | Pages | 136-44 |
| PubMed ID | 12054753 | Mgi Jnum | J:77027 |
| Mgi Id | MGI:2180918 | Doi | 10.1016/S0006-291X(02)00449-7 |
| Citation | Dong LQ, et al. (2002) Cloning and characterization of a testis and brain-specific isoform of mouse 3'-phosphoinositide-dependent protein kinase-1, mPDK-1 beta. Biochem Biophys Res Commun 294(1):136-44 |
| abstractText | 3'-Phosphoinositide-dependent protein kinase-1 (PDK-1) phosphorylates and activates members of the protein kinase AGC family and plays a key role in receptor tyrosine kinase signaling. Here we report the cloning and characterization of a splice variant of mouse PDK-1, mPDK-1 beta. The cDNA encoding mPDK-1 beta contains two alternative start codons and translation from these start codons generates proteins that are, respectively, 27 or 51 amino acid residues shorter at the amino-terminus than the previously identified PDK-1 isolated from mouse liver (now renamed mPDK-1 alpha) [J. Biol. Chem. 274 (1999) 8117]. Analysis of mouse tissues shows that mPDK-1 beta is highly expressed in the testis and various functional regions of the brain. Expression of this isoform is increased in the brain of aged mice. Both mPDK-1 alpha and mPDK-1 beta are autophosphorylated at both serine and threonine residues in vitro and showed similar levels of tyrosine phosphorylation when co-expressed with either constitutively active Src or Fyn tyrosine kinases in cells. However, the mPDK-1 isoforms showed significant differences in their response to pervanadate- or insulin plus vanadate-stimulated tyrosine phosphorylation. Taken together, our findings suggest that the two PDK-1 isoforms may be differentially regulated in cells. The specific expression of mPDK-1 beta in mouse testis and brains of aged mice also suggests potential involvement of this kinase in regulating animal spermatogenesis and aging. |
