PBS2, a yeast gene encoding a putative protein kinase, interacts with the RAS2 pathway and affects osmotic sensitivity of Saccharomyces cerevisiae.
The yeast gene PBS2 encodes a presumed protein kinase. The gene is essential for manifestation of resistance to the antibiotic polymyxin B. Deletion of PBS2 enables a ras2-530 null mutant to grow on nonfermentable carbon sources; overexpression of PBS2+ enhances viability of a RAS2Val19 mutant. Overexpression of PBS2+ also diminishes cellular response to mating pheromone MF alpha. These results suggest that the PBS2 and RAS2 genes affect a common pathway that may communicate with the pheromone response pathway. In addition, disruption of PBS2 renders cells sensitive to high osmolarity: exposure to 0.9 M-NaCl causes growth arrest, appearance of bizarre morphological forms, and eventual death. A mutation suppressing pbs2 deletion has been found. That mutation restores full polymyxin B resistance but only partially corrects the osmotic sensitivity defect. These observations indicate that PBS2 is involved in diverse physiological pathways in yeast.
Boguslawski
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Department of Medicine, Indiana University School of Medicine, Indianapolis 46202.
D002244:Carbon / Q000378:metabolism; D004352:Drug Resistance, Microbial; D017353:Gene Deletion; D005800:Genes, Fungal / Q000235:genetics*; D009996:Osmotic Fragility / Q000235:genetics*; D010675:Pheromones / Q000494:pharmacology; D011112:Polymyxin B / Q000494:pharmacology; D011494:Protein Kinases / Q000235:genetics*; D012441:Saccharomyces cerevisiae / Q000166:cytology / Q000187:drug effects / Q000201:enzymology / Q000235:genetics*; D015398:Signal Transduction; D012965:Sodium Chloride / Q000494:pharmacology; D013489:Suppression, Genetic
D010675:Pheromones; D012965:Sodium Chloride; D002244:Carbon; D011494:Protein Kinases; D011112:Polymyxin B