Identification of yin-yang regulators and a phosphorylation consensus for male germ cell-associated kinase (MAK)-related kinase.
MAK (male germ cell-associated protein kinase) and MRK/ICK (MAK-related kinase/intestinal cell kinase) are human homologs of Ime2p in Saccharomyces cerevisiae and of Mde3 and Pit1 in Schizosaccharomyces pombe and are similar to human cyclin-dependent kinase 2 (CDK2) and extracellular signal-regulated kinase 2 (ERK2). MAK and MRK require dual phosphorylation in ... a TDY motif catalyzed by an unidentified human threonine kinase and tyrosine autophosphorylation. Herein, we establish that human CDK-related kinase CCRK (cell cycle-related kinase) is an activating T157 kinase for MRK, whereas active CDK7/cyclin H/MAT1 complexes phosphorylate CDK2 but not MRK. Protein phosphatase 5 (PP5) interacts with MRK in a complex and dephosphorylates MRK at T157 in vitro and in situ. Thus, CCRK and PP5 are yin-yang regulators of T157 phosphorylation. To determine a substrate consensus, we screened a combinatorial peptide library with active MRK. MRK preferentially phosphorylates R-P-X-S/T-P sites, with the preference for arginine at position -3 (P-3) being more stringent than for prolines at P-2 and P+1. Using the consensus, we identified a putative phosphorylation site (RPLT(1080)S) for MRK in human Scythe, an antiapoptotic protein that interacts with MRK. MRK phosphorylates Scythe at T1080 in vitro as determined by site-directed mutagenesis and mass spectrometry, supporting the consensus and suggesting Scythe as a physiological substrate for MRK.
Mesh Terms:
Amino Acid Motifs, Amino Acid Sequence, Cell Line, Consensus Sequence, Cyclin-Dependent Kinases, Down-Regulation, Gene Expression Regulation, Humans, Hydrogen Peroxide, Molecular Chaperones, Molecular Sequence Data, Nuclear Proteins, Phosphoprotein Phosphatases, Phosphorylation, Protein Structure, Tertiary, Protein-Serine-Threonine Kinases, Proteins, Transfection
Amino Acid Motifs, Amino Acid Sequence, Cell Line, Consensus Sequence, Cyclin-Dependent Kinases, Down-Regulation, Gene Expression Regulation, Humans, Hydrogen Peroxide, Molecular Chaperones, Molecular Sequence Data, Nuclear Proteins, Phosphoprotein Phosphatases, Phosphorylation, Protein Structure, Tertiary, Protein-Serine-Threonine Kinases, Proteins, Transfection
Mol. Cell. Biol.
Date: Nov. 01, 2006
PubMed ID: 16954377
View in: Pubmed Google Scholar
Download Curated Data For This Publication
70743
Switch View:
- Interactions 8