Details

Autor(en) / Beteiligte

• Howard, S.C
• Deminoff, S.J
• Herman, P.K

Titel

Increased phosphoglucomutase activity suppresses the galactose growth defect associated with elevated levels of Ras signaling in S. cerevisiae

Ist Teil von

• Current genetics, 2006, Vol.49 (1), p.1-6

Ort / Verlag

United States: Springer Nature B.V

Erscheinungsjahr

2006

Quelle

MEDLINE

Beschreibungen/Notizen

• The Ras proteins regulate many aspects of cell growth in the budding yeast, Saccharomyces cerevisiae, via the cAMP-dependent protein kinase (PKA). Here, we show that a RAS2 val¹⁹ mutant that exhibits elevated levels of Ras/PKA signaling activity is unable to grow on media with galactose as the sole source of carbon. This growth defect was due, at least in part, to a defect in the expression of genes, like GAL1, that encode enzymes needed for the metabolism of galactose. This growth defect was used as the basis for a genetic screen for dosage suppressors of the RAS2 val¹⁹ mutant. This screen identified two genes, PGM1 and PCM1, that encode proteins with phosphoglucomutase activity. This activity is responsible for converting the glucose-1-phosphate produced during the metabolism of galactose to glucose-6-phosphate, a precursor that can be metabolized via the glycolytic pathway. The over-expression of PGM1 was not able to suppress any other RAS2 val¹⁹ phenotype or the galactose growth defect associated with a gal1Δ mutant. Overall, these data suggest that the elevated levels of phosphoglucomutase activity allow for the more efficient utilization of the limiting levels of glucose-1-phosphate that are present in the RAS2 val¹⁹ mutant.