First Author | Abe Y | Year | 2000 |
Journal | J Biol Chem | Volume | 275 |
Issue | 28 | Pages | 21525-31 |
PubMed ID | 10781613 | Mgi Jnum | J:87495 |
Mgi Id | MGI:3026604 | Doi | 10.1074/jbc.M909629199 |
Citation | Abe Y, et al. (2000) Cloning and expression of a novel MAPKK-like protein kinase, lymphokine-activated killer T-cell-originated protein kinase, specifically expressed in the testis and activated lymphoid cells. J Biol Chem 275(28):21525-31 |
abstractText | A novel protein kinase, TOPK (T-LAK cell-originated protein kinase), was isolated from a lymphokine-activated killer T (T-LAK) cell subtraction cDNA fragment library. The open reading frame of the TOPK gene encodes a protein of 322 amino acids, possessing a protein kinase domain profile. The cap site analysis of the 5'-end of TOPK mRNA revealed two forms, a major full-length form and a minor spliced form at the 5'-site, both encoding the same protein. A BLAST homology search and phylogenetic analysis indicated that TOPK is related to dual specific mitogen-activated protein kinase kinase (MAPKK). The transfection of the TOPK gene to COS-7 cells up-regulated a phosphorylation of p38 MAPK but not ERK1/2 or SAPK/JNK. Gel precipitation study indicated that TOPK protein can be associated with p38 in vitro. Tissue distribution of TOPK mRNA expression was specific for the testis, T-LAK cells, activated lymphoid cells, and lymphoid tumors. On the other hand, deactivated T-LAK cells did not show TOPK mRNA expression. These data suggest that TOPK is a newly identified member of a novel MEK3/6-related MAPKK that may be enrolled in the activation of lymphoid cells and support testicular functions. |