Global Analysis of Serine-Threonine Protein Kinase Genes in Neurospora crassa
ABSTRACTSerine/threonine (S/T) protein kinases are crucial components of diverse signaling pathways in eukaryotes, including the model filamentous fungusNeurospora crassa. In order to assess the importance of S/T kinases toNeurosporabiology, we embarked on a global analysis of 86 S/T kinase genes inNeurospora. We were able to isolate viable mutants for 77 of the 86 kinase genes. Of these, 57% exhibited at least one growth or developmental phenotype, with a relatively large fraction (40%) possessing a defect in more than one trait. S/T kinase knockouts were subjected to chemical screening using a panel of eight chemical treatments, with 25 mutants exhibiting sensitivity or resistance to at least one chemical. This brought the total percentage of S/T mutants with phenotypes in our study to 71%. Mutants lackingapg-1, an S/T kinase required for autophagy in other organisms, possessed the greatest number of phenotypes, with defects in asexual and sexual growth and development and in altered sensitivity to five chemical treatments. We showed that NCU02245/stk-19is required for chemotropic interactions between female and male cells during mating. Finally, we demonstrated allelism between the S/T kinase gene NCU00406 andvelvet(vel), encoding a p21-activated protein kinase (PAK) gene important for asexual and sexual growth and development inNeurospora.