A series of double disruptants for protein phosphatase genes in Saccharomyces cerevisiae and their phenotypic analysis

Abstract

Thirty-two protein phosphatase (PPase) genes were identified in Saccharomyces cerevisiae based on the nucleotide sequences of the entire genome. In an effort to understand the role of PPases and their functional redundancy in the cellular physiology of one of the reference eukaryotic organisms, a series of single and double PPase gene disruptants were constructed in the W303 strain background. Two single disruptants for the CDC14 and GLC7 genes were lethal. Double disruptants for 30 non-essential PPase genes were constructed in all possible 435 combinations. No double disruptant showed synthetic lethality. Several phenotypes of the viable 30 single and 435 double disruptants were examined; temperature-sensitive growth, utilization of carbon sources and sensitivity to cations and drugs. Four double disruptants exhibited synthetic phenotypes in addition to eight single ones: the pph21 pph22 double disruptant showed slow growth on complete medium, as did the sit4 and yvh1 single ones. In addition to the ptc1, ynr022c and ycr079w single disruptants, the ppz1 ppz2 double disruptant showed temperature-sensitive slow growth. The msg5 ptp2 double disruptant, like the ynr022c single one, did not grow on complete medium containing 0.3 M CaCl 2 . The double msg5 ptc2 disruptant failed to grow on medium containing 1.0 M NaCl and, like the ynr022c single deletion, also could not grow on medium containing 0.3 M CaCl 2 . The synthetic phenotypes in the two latter cases where each of the PPases is categorized in a different phosphatase family led us to discuss the novel mechanism involved in the functional redundancy of the PPases.

A Mutant Plasma Membrane Protein Is Stabilized Upon Loss of Yvh1, a Novel Ribosome Assembly Factor

“…Like many ribosome mutants, yvh1D cells are cold sensitive (Sakumoto et al 2002). Evidence from several previous studies supports our conclusion that Yvh1 participates in 60S ribosomal subunit biogenesis.…”

Yeast Pyruvate Dehydrogenase Complex Is Regulated by a Concerted Activity of Two Kinases and Two Phosphatases

“…The result is interesting in light of the fact that different functions have been implicated for this protein in previous studies. It was reported that Ppp2p is involved in the process of mitophagy (38) and confers a rapamycin-resistant function (45), and its deletion results in a caffeine-sensitive phenotype (60). We assume that these pleiotropic phenotypes are likely due to the critical role of PDC in the metabolism by supplying acetyl-CoA.…”

Regulation of ENA1 Na + -ATPase Gene Expression by the Ppz1 Protein Phosphatase Is Mediated by the Calcineurin Pathway

“…The observations that a ppz1 mutant is sensitive to calcium ions, as would be expected for a strain with higher-than-normal calcineurin activity, and that this sensitivity is fully abolished by deletion of cnb1 are in agreement with this model. It should be noted that a previous report failed to identify a ppz1 mutant as calcium sensitive (42). These authors based their work in a genetic background (W303-1A-derived strains) different from those used in this work.…”