A series of protein phosphatase gene disruptants inSaccharomyces cerevisiae

Sakumoto, Naoko; Mukai, Yoshihiko; Uchida, Kouji; Kouchi, T.; Kuwajima, Jyoh; Nakagawa, Youji; Sugioka, Shigemi; Yamamoto, Eishi; Furuyama, Tatsuo; Mizubuchi, Hiroyuki; Ohsugi, Naoshi; Sakuno, Takeshi; Kikuchi, Kunio; Matsuoka, Itsumi; Ogawa, Norio; Kaneko, Yoshinobu; Harashima, Satoshi

doi:10.1002/(sici)1097-0061(199911)15:15<1669::aid-yea480>3.0.co;2-6

Cited by 102 publications

(84 citation statements)

References 49 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…For instance, Sac. cerevisiae has approximately 6000 genes, of which 113 encode protein kinase genes, but only 31 encode protein phosphatases (Dickman & Yarden, 1999;Sakumoto et al, 1999;Stark, 1996). Considering the deviation in prevalence between protein kinases and protein phosphatases, it is likely that Cpp1 has broad substrate specificity, and interacts with multiple protein kinases in several signalling pathways.…”

Section: Discussionmentioning

confidence: 99%

Functional characterization of Fusarium verticillioides CPP1, a gene encoding a putative protein phosphatase 2A catalytic subunit

Choi

Shim

2008

Microbiology

View full text Add to dashboard Cite

Fusarium verticillioides produces the mycotoxin fumonisin B 1 (FB 1 ) on maize kernels. In this study, we identified a putative protein phosphatase gene CPP1 in F. verticillioides, and investigated its role in FB 1 regulation. Previous work has shown that CPP1 expression is elevated in an FB 1 -suppressing genetic background. Thus, we hypothesized that CPP1 is negatively associated with FB 1 production. To test this hypothesis, we generated a CPP1 knockout mutant, PP179, and studied the effects of gene deletion on FB 1 biosynthesis and fungal development. PP179 showed elevated expression of FUM genes, and in turn produced higher levels of FB 1 than the wild-type progenitor. Other significant mutant phenotypes included reduced radial growth on agar plates, reduced conidia germination rates, significantly increased macroconidia formation, and hyphal swelling. To verify that these phenotypes were directly due to CPP1 deletion, we complemented PP179 with the wild-type CPP1 gene. The complemented strain PPC4 showed FUM1 expression and FB 1 production similar to that of the wild-type, providing evidence that CPP1 is negatively associated with FB 1 biosynthesis. Other PP179 phenotypes, such as macroconidiation and hyphal swelling, were also restored to that of wild-type progenitor. Furthermore, we complemented F. verticillioides PP179 strain with Neurospora crassa wild-type ppe-1 gene, demonstrating that Cpp1 and PPE-1 proteins are functionally conserved. Pleiotropic effects of CPP1 deletion led us to hypothesize that CPP1 is associated with multiple downstream signalling pathways in F. verticillioides. Identification and functional characterization of downstream Cpp1-interacting proteins are necessary to better understand the complex regulatory mechanisms associated with Cpp1.

show abstract

Section: Discussionmentioning

confidence: 99%

Functional characterization of Fusarium verticillioides CPP1, a gene encoding a putative protein phosphatase 2A catalytic subunit

Choi

Shim

2008

Microbiology

View full text Add to dashboard Cite

show abstract

“…2), we also tested whether aup1⌬ and atg1⌬ cells are defective in stationary phase mitophagy. AUP1 was previously shown to be a nonessential gene (36). As shown in Fig.…”

Section: Aup1p Is Required For Efficient Mitophagicmentioning

confidence: 94%

Aup1p, a Yeast Mitochondrial Protein Phosphatase Homolog, Is Required for Efficient Stationary Phase Mitophagy and Cell Survival

Tal

Winter

Ecker

et al. 2007

Journal of Biological Chemistry

249

246

View full text Add to dashboard Cite

Autophagy is a catabolic membrane-trafficking process that occurs in all eukaryotic cells and leads to the hydrolytic degradation of cytosolic material in the vacuolar or lysosomal lumen. Mitophagy, a selective form of autophagy targeting mitochondria, is poorly understood at present. Several recent reports suggest that mitophagy is a selective process that targets damaged mitochondria, whereas other studies imply a role for mitophagy in cell death processes. In a screen for protein phosphatase homologs that functionally interact with the autophagy-dedicated protein kinase Atg1p in yeast, we have identified Aup1p, encoded by Saccharomyces cerevisiae reading frame YCR079w. Aup1p is highly similar to a family of protein phosphatase homologs in animal cells that are predicted to localize to mitochondria based on sequence analysis. Interestingly, we found that Aup1p localizes to the mitochondrial intermembrane space and is required for efficient mitophagy in stationary phase cells. Viability studies demonstrate that Aup1p is required for efficient survival of cells in prolonged stationary phase cultures, implying a pro-survival role for mitophagy under our working conditions. Our data suggest that Aup1p may be part of a signal transduction mechanism that marks mitochondria for sequestration into autophagosomes.Mitochondria perform numerous essential physiological functions in all eukaryotic cells. Apart from their role in oxidative phosphorylation and fatty acid oxidation, they are also essential for biosynthesis of central building blocks such as amino acids and nucleotides. At the same time, mitochondria are a threat to cellular well-being. Mitochondria are a major source of reactive oxygen species in cells. In addition, disruption of mitochondrial compartmentalization results in leakage of cytochrome c and other cytotoxic factors, and mitochondria with defective chemiosmotic coupling can cause an energy drain on the cell. Accumulation of mitochondrial genetic variation and mitochondrial damage are widely considered to underlie many age-related metabolic diseases and late-onset genetic disorders (1, 2). It is commonly postulated that in normal cells defective mitochondria are broken down in the lysosomal compartment through autophagy, and inability to clear defective mitochondria is thought to underlie numerous pathological conditions (3, 4).Autophagy is a set of catabolic membrane trafficking mechanisms that allow import of cytosolic material into the vacuole/ lysosome. The best understood form of autophagy is macroautophagy, in which intracellular membranes of undetermined origin engulf cytosolic material to form a double or multi-bilayer membrane bound intermediate called the autophagosome (reviewed in Refs. 3 and 5-8). This intermediate then goes on to fuse with the vacuole/lysosome, releasing a single-bilayer bound vesicle called an autophagic body into the lumen of the lytic compartment where it is broken down, releasing the cytosol-derived material for further degradation to biosynthetic building blocks. Cl...

show abstract

“…Deletions of MYO4, KHD1, MKT1, PBP1, and ASH1 were constructed by the PCR-based gene deletion method (1,28,30). Primer sets were designed such that 46 bases at the 5Ј end of the primers were complementary to those at the corresponding region of the target gene and 20 bases at their 3Ј end were complementary to the pUC19 sequence outside the polylinker region in plasmid pCgHIS3 containing the Candida glabrata HIS3 gene, plasmid pCgTRP1 containing the C. glabrata TRP1 gene, or plasmid pCgLEU2 containing the C. glabrata LEU2 gene as a selectable marker.…”

Section: Methodsmentioning

confidence: 99%

Posttranscriptional Regulation of HO Expression by the Mkt1-Pbp1 Complex

Tadauchi

Inada

Matsumoto

et al. 2004

Molecular and Cellular Biology

View full text Add to dashboard Cite

Cells of budding yeast give rise to mother and daughter cells, which differ in that only mother cells express the HO endonuclease gene and are thereby able to switch mating types. In this study, we identified the MKT1 gene as a positive regulator of HO expression. The MKT1 gene encodes a protein with two domains, XPG-N and XPG-I, which are conserved among a family of nucleases, including human XPG endonuclease. Loss of MKT1 had little effect on HO mRNA levels but resulted in decreased protein levels. This decrease was dependent on the 3 untranslated region of the HO transcript. We screened for proteins that associate with Mkt1 and isolated Pbp1, a protein that is known to associate with Pab1, a poly(A)-binding protein. Loss of PBP1 resembles an mkt1⌬ deletion, causing decreased expression of HO at the posttranscriptional level. Mkt1 and Pbp1 cosedimented with polysomes in sucrose gradients, with Mkt1 distribution in the polysomes dependent on Pbp1, but not vice versa. These observations suggest that a complex of Mkt1 and Pbp1 regulates the translation of HO mRNA.Gene expression can be regulated at multiple steps, including transcription, splicing, mRNA transport, mRNA stability, and translation. Regulation of mRNA translation depends on a temporally and spatially orchestrated sequence of proteinprotein, protein-RNA, and RNA-RNA interactions. Posttranscriptional regulation plays an important role during the development of a wide variety of organisms (7). For example, the asymmetric patterns of gene expression in Xenopus and Drosophila embryos are determined by the differential localization, stabilization, and translation of maternally synthesized mRNAs. Translational regulation also plays a key role in germ line sex determination in Caenorhabditis elegans (6,14,39). In most of the cases studied in detail, posttranscriptional regulation is mediated by sites in the 3Ј untranslated region (UTR) of the target mRNA.The HO endonuclease initiates mating-type switching in Saccharomyces cerevisiae by creating a double-stranded break at the MAT locus (9). The HO gene is only transcribed in mother cells, i.e., cells that have previously budded and given birth to a daughter cell. In mother cells, HO is transcribed transiently during the cell cycle, shortly before budding and DNA replication (24). Activation of HO transcription depends on at least 10 genes, named SWI1 through SWI10. SWI4 and SWI6 encode subunits of a cell cycle-regulated transcription factor, SCB-binding factor, that activates a number of genes at the G 1 /S boundary (17). SWI1, SWI2, SWI3, and SWI10 encode components of a large multisubunit complex that is needed for the expression of many yeast genes (26).Asymmetric transcription of the HO gene results from the preferential accumulation of a negative regulatory protein, Ash1, in daughter nuclei (3, 32). ASH1 mRNA is targeted to the distal tip of daughter buds in postanaphase cells (18,35). Localization of ASH1 mRNA depends on an intact actin cytoskeleton and five SHE genes (15,18,35). SHE1 encodes a type V ...

show abstract

A series of protein phosphatase gene disruptants inSaccharomyces cerevisiae

Cited by 102 publications

References 49 publications

Functional characterization of Fusarium verticillioides CPP1, a gene encoding a putative protein phosphatase 2A catalytic subunit

Functional characterization of Fusarium verticillioides CPP1, a gene encoding a putative protein phosphatase 2A catalytic subunit

Aup1p, a Yeast Mitochondrial Protein Phosphatase Homolog, Is Required for Efficient Stationary Phase Mitophagy and Cell Survival

Posttranscriptional Regulation of HO Expression by the Mkt1-Pbp1 Complex

Contact Info

Product

Resources

About