Effect of Cryphonectria hypovirus 1 (CHV1) infection on Cpkk1, a mitogen-activated protein kinase kinase of the filamentous fungus Cryphonectria parasitica.
We screened Cryphonectria parasitica genomic and cDNA libraries with a probe obtained from the amplification of a conserved region among the sequence of known mitogen activated protein kinase kinases (MAPKK) and obtained genomic and cDNA clones. Sequence comparisons of the clones obtained confirmed the identification of a C. parasitica homologue to other fungal MAPKK, which we named Cpkk1. Polyclonal antibodies raised against a purified Cpkk1 fusion protein expressed in Escherichia coli were used to detect Cpkk1 protein in extracts of CHV1-infected and uninfected C. parasitica grown in liquid culture. Differences in the dynamics of phosphorylation and dephosphorylation were noticed. Under the conditions investigated, Cpkk1 protein expression is associated with active mycelial growth, before the onset of a senescent developmental stage. We hypothesize that differences in Cpkk1 phosphorylation state between CHV1 infected and virus free strains are due to a delay of the onset of the developmental stage caused by the presence of the virus.
Turina
M
M
Department of Plant Pathology, University of California, One Shield Ave., Davis, CA 95616, USA.
Zhang
L
L
Van Alfen
Neal K
NK
D000595:Amino Acid Sequence; D015971:Gene Expression Regulation, Enzymologic / Q000235:genetics; D015966:Gene Expression Regulation, Fungal / Q000235:genetics; D020929:Mitogen-Activated Protein Kinase Kinases / Q000096:biosynthesis* / Q000235:genetics; D008969:Molecular Sequence Data; D025282:Mycelium / Q000201:enzymology / Q000235:genetics / Q000821:virology; D010766:Phosphorylation; D011499:Protein Processing, Post-Translational / Q000235:genetics; D012328:RNA Viruses; D020037:Sordariales / Q000201:enzymology* / Q000235:genetics / Q000821:virology*
D020929:Mitogen-Activated Protein Kinase Kinases