Disease relevance of KSS1

• Either FUS3 or KSS1 can execute this function; when neither gene encoding these protein kinases is present, signal transduction is blocked, causing sterility [1].
• Osmolarity hypersensitivity of hog1 deleted mutants is suppressed by mutation in KSS1 in budding yeast Saccharomyces cerevisiae [2].

High impact information on KSS1

• The predicted FUS3 protein is 35% identical to the cdc2+/CDC28 kinases and 52% identical to the KSS1 predicted kinase [3].
• The KSS1 gene encodes an apparent protein kinase homologous to the CDC28 (S. cerevisiae) and cdc2+ (S. pombe) gene products [4].
• Because SST2 product and the receptor tail contribute independently to events that allow recovery from pheromone-induced growth arrest, KSS1 function defines a third independent process that promotes desensitization [4].
• Both developmental alternatives to vegetative proliferation require the MAP kinase Kss1 and the transcriptional transactivator Ste12 [5].
• Differential regulation of transcription: repression by unactivated mitogen-activated protein kinase Kss1 requires the Dig1 and Dig2 proteins [6].

Biological context of KSS1

• This functional redundancy is strain dependent; some standard laboratory strains (S288C) are kss1-. FUS3 has additional functions required for cell cycle arrest and vegetative growth that do not overlap with KSS1 functions [1].
• Since CEK1 confers a phenotype similar to that of the structurally related S. cerevisiae gene KSS1 but cannot complement a KSS1 defect, it is evident that dominant negative selection can identify proteins that complementation screens would miss [7].
• MSB2 is located between the centromere and KSS1 on the right arm of chromosome VII [8].
• Strains isogenic to S288C used in the yeast genome sequencing programme carry a functional KSS1 gene [9].
• Here, we report evidence that S288C derivatives used in the Yeast Genome Sequencing Programme carry a functional KSS1 gene and can thus be used to study the regulation of gene expression by KSS1 [9].

Other interactions of KSS1

• Expression of Xenopus MAP kinase suppressed the defect associated with loss of MPK1 but not the mating-related defects associated with loss of FUS3 or KSS1, indicating functional conservation between the former two protein kinases [10].
• Additionally, the cellular projections formed by a pbs2-3 mutant on high osmolarity are absent in strains lacking KSS1 or STE7 [11].
• The mutation in KSS1 suppresses the osmolarity-hypersensitive phenotype of the hog1 deletion mutation and restores GPD1 induction [2].

References