MAP kinase kinase from rabbit skeletal muscle. A novel dual specificity enzyme showing homology to yeast protein kinases involved in pheromone-dependent signal transduction.
MAP kinase kinase (MAPKK) was purified 30,000-fold to homogeneity from extracts of rabbit skeletal muscle and shown to be a monomeric protein of apparent molecular mass 44 kDa. MAPKK activated the 42 kDa isoform of MAP kinase by phosphorylation of Thr-183 and Tyr-185, and phosphorylated itself slowly on tyrosine, threonine and serine residues, establishing that it is a 'dual specificity' protein kinase. Peptide sequences from MAPKK were homologous to other protein serine/threonine kinases, especially to the subfamily that includes yeast protein kinases that lie upstream of yeast MAP kinase homologues in the pheromone-dependent mating pathways.
Nakielny
S
S
Department of Biochemistry, University of Dundee, Scotland, UK.
Campbell
D G
DG
Cohen
P
P
D000595:Amino Acid Sequence; D000818:Animals; D002853:Chromatography, Liquid; D004591:Electrophoresis, Polyacrylamide Gel; D051379:Mice; D020929:Mitogen-Activated Protein Kinase Kinases; D008969:Molecular Sequence Data; D009132:Muscles / Q000201:enzymology*; D010449:Peptide Mapping; D010675:Pheromones / Q000378:metabolism*; D011494:Protein Kinases / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D011817:Rabbits; D012441:Saccharomyces cerevisiae / Q000201:enzymology*; D012689:Sequence Homology, Nucleic Acid; D015398:Signal Transduction; D013379:Substrate Specificity; D014357:Trypsin
D010675:Pheromones; D011494:Protein Kinases; D020929:Mitogen-Activated Protein Kinase Kinases; D014357:Trypsin