Cloning and characterization of RLPK, a novel RSK-related protein kinase
| Autor: | William W. Bassett, Ming Zhao, Stephen Ludwig, Di Padova Franco E, Jiahuai Han, Hermann Gram, Yue Feng, Liguo New, Yingqiu Li |
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| Rok vydání: | 1999 |
| Předmět: |
DNA
Complementary Molecular Sequence Data Mitogen-activated protein kinase kinase Protein Serine-Threonine Kinases Biochemistry Ribosomal Protein S6 Kinases 90-kDa MAP2K7 Humans ASK1 c-Raf Amino Acid Sequence Kinase activity Cloning Molecular Phosphorylation Molecular Biology biology MAP kinase kinase kinase Sequence Homology Amino Acid Cyclin-dependent kinase 2 Cell Biology Molecular biology Cell biology Enzyme Activation Calcium-Calmodulin-Dependent Protein Kinases biology.protein Cyclin-dependent kinase 9 Cell Division HeLa Cells |
| Zdroj: | The Journal of biological chemistry. 274(2) |
| ISSN: | 0021-9258 |
| Popis: | A novel protein kinase whose activity can be stimulated by mitogen in vivo was cloned and characterized. The cDNA of this gene encodes an 802-amino acid protein (termed RLPK) with the highest homology (37% identity) to the two protein kinase families, p90(RSK) and p70(RSK). Like p90(RSR), but not p70(RSK), RLPK also contains two complete nonidentical protein kinase domains. RLPK mRNA is widely expressed in all human tissues examined and is enriched in the brain, heart, and placenta. In HeLa cells, transiently expressed epitope-tagged RLPK can be strongly induced by epidermal growth factor, serum, and phorbol 12-myristate 13-acetate, but only moderately up-regulated by tumor necrosis factor-alpha and other stress-related stimuli. The activity of RLPK stimulated by epidermal growth factor was not inhibited by several known protein kinase C inhibitors nor by rapamycin, a known specific inhibitor for p70(RSK), but could be inhibited by herbimycin A, a tyrosine kinase inhibitor, and partially inhibited by PD98059 or SB203580, inhibitors for the mitogen-activated protein kinase pathways. Recombinant RLPK possesses high phosphorylation activity toward histone 2B and the S6 peptide, RRRLSSLRA. Although purified recombinant RLPK can be phosphorylated by ERK2 and p38alpha in vitro, its activity is not affected by this phosphorylation. Moreover, the treatment of RLPK with acid phosphatase did not reduce its in vitro kinase activity. These data suggest that RLPK is structurally similar to previously isolated RSKs, but its regulatory mechanism may be distinct from either p70(RSK) or p90(RSK)s. |
| Databáze: | OpenAIRE |
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