Characterization of a mitogen-activated protein kinase from Pneumocystis carinii.
The pathogenic fungus Pneumocystis carinii causes severe pneumonia in patients with impaired immunity, particularly patients with acquired immunodeficiency syndrome. The life cycle of P. carinii is poorly understood, and the inability to continuously culture P. carinii is a major limitation in understanding its cell biology. In fungi homologous to P. carinii, pheromone mating factors signal through a mitogen-activated protein kinase (MAPK) signal transduction cascade, resulting in mitotic cell cycle arrest and entry into a pathway of conjugation, cellular differentiation, and proliferation. Using degenerate PCR and library screening, we have identified a MAPK cDNA in P. carinii that is highly homologous to fungal MAPKs involved in the pheromone mating signal transduction cascade, and we demonstrate MAPK activity in P. carinii lysates with a specific antiserum derived from the translated P. carinii MAPK cDNA sequence.
Thoracic Diseases Research Unit, Division of Pulmonary, Critical Care and Internal Medicine, Mayo Clinic and Foundation, Rochester, Minnesota 55905, USA.
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D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D017871:Calcium-Calmodulin-Dependent Protein Kinases / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D002874:Chromosome Mapping; D015825:Chromosomes, Fungal; D003001:Cloning, Molecular; D005658:Fungi / Q000201:enzymology; D015723:Gene Library; D006801:Humans; D007700:Kinetics; D008969:Molecular Sequence Data; D011010:Pneumocystis / Q000201:enzymology* / Q000235:genetics; D016133:Polymerase Chain Reaction; D051381:Rats; D011994:Recombinant Proteins / Q000737:chemistry / Q000378:metabolism; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid
D011994:Recombinant Proteins; D017871:Calcium-Calmodulin-Dependent Protein Kinases