cd06620: PKc_MAPKK_Byr1_like (this model, PSSM-Id:132951 is obsolete and has been replaced by 270792)
Catalytic domain of fungal Byr1-like dual-specificity MAP kinase kinases
Protein kinases (PKs), MAP kinase kinase (MAPKK) subfamily, fungal Byr1-like proteins, catalytic (c) domain. PKs catalyze the transfer of the gamma-phosphoryl group from ATP to serine/threonine or tyrosine residues on protein substrates. The MAPKK subfamily is part of a larger superfamily that includes the catalytic domains of other protein serine/threonine kinases, protein tyrosine kinases, RIO kinases, aminoglycoside phosphotransferase, choline kinase, and phosphoinositide 3-kinase. The mitogen-activated protein (MAP) kinase signaling pathways are important mediators of cellular responses to extracellular signals. The pathways involve a triple kinase core cascade comprising of the MAP kinase (MAPK), which is phosphorylated and activated by a MAPK kinase (MAPKK or MKK), which itself is phosphorylated and activated by a MAPK kinase kinase (MAPKKK or MKKK). Members of this group include the MAPKKs Byr1 from Schizosaccharomyces pombe, FUZ7 from Ustilago maydis, and related proteins. Byr1 phosphorylates its downstream target, the MAPK Spk1, and is regulated by the MAPKKK Byr2. The Spk1 cascade is pheromone-responsive and is essential for sporulation and sexual differentiation in fission yeast. FUZ7 phosphorylates and activates its target, the MAPK Crk1, which is required in mating and virulence in U. maydis.