scholarly journals Inactivation of fission yeast Erh1 de-represses pho1 expression: evidence that Erh1 is a negative regulator of prt lncRNA termination

RNA ◽  
2020 ◽  
Vol 26 (10) ◽  
pp. 1334-1344 ◽  
Author(s):  
Beate Schwer ◽  
Ana M. Sanchez ◽  
Stewart Shuman
Keyword(s):  
Fission Yeast ◽  
Negative Regulator ◽  
Expression Evidence

scholarly journals The Scw1 RNA-Binding Domain Protein Regulates Septation and Cell-Wall Structure in Fission Yeast

Genetics ◽  
2002 ◽  
Vol 162 (1) ◽  
pp. 45-58 ◽  
Author(s):  
Jim Karagiannis ◽  
Rena Oulton ◽  
Paul G Young
Keyword(s):  
Cell Wall ◽  
Fission Yeast ◽  
Rna Binding ◽  
Binding Domain ◽  
Negative Regulator ◽  
Wall Structure ◽  
Cell Wall Degrading Enzymes ◽  
Degrading Enzymes ◽  
Domain Protein ◽  
Rna Binding Domain

AbstractLoss of the nonessential RNA-binding domain protein, Scw1, increases resistance to cell-wall-degrading enzymes in fission yeast. Surprisingly, scw1 null mutations also suppress the lethality of mutations (cdc11-136, cdc7-24, cdc14-118, sid1-239, sid2-250, sid3-106, sid4-A1, and mob1-1) at all levels of the sid pathway. This pathway forms part of the septation initiation network (SIN), which regulates the onset of septum formation and ensures the proper coupling of mitosis to cytokinesis. In contrast, scw1- mutations do not suppress ts alleles of the rng genes, cdc12 or cdc15. These mutations also prevent the formation of a septum and in addition block assembly and/or function of the contractile acto-myosin ring. sid mutants exhibit a hyper-sensitivity to cell-wall-degrading enzymes that is suppressed by loss of Scw1. Furthermore, scw1--mediated rescue of sid mutants is abolished in the presence of calcofluor white, a compound that interferes with cell-wall synthesis. These data suggest that Scw1 acts in opposition to the SIN as a negative regulator of cell-wall/septum deposition. Unlike components of the SIN, Scw1 is predominantly a cytoplasmic protein and is not localized to the spindle pole body.

scholarly journals The Fission Yeast git5 Gene Encodes a Gβ Subunit Required for Glucose-Triggered Adenylate Cyclase Activation

Genetics ◽  
2000 ◽  
Vol 154 (4) ◽  
pp. 1463-1471 ◽  
Author(s):  
Sheila Landry ◽  
Maria T Pettit ◽  
Ethel Apolinario ◽  
Charles S Hoffman
Keyword(s):  
Adenylate Cyclase ◽  
Fission Yeast ◽  
Coiled Coil ◽  
Negative Regulator ◽  
Guanine Nucleotide Binding Protein ◽  
Amino Terminal ◽  
Cyclase Activation ◽  
Adenylate Cyclase Activation ◽  
Guanine Nucleotide Binding ◽  
Camp Levels

Abstract Fission yeast adenylate cyclase is activated by the gpa2 Gα subunit of a heterotrimeric guanine-nucleotide binding protein (G protein). We show that the git5 gene, also required for this activation, encodes a Gβ subunit. In contrast to another study, we show that git5 is not a negative regulator of the gpa1 Gα involved in the pheromone response pathway. While 43% identical to mammalian Gβ's, the git5 protein lacks the amino-terminal coiled-coil found in other Gβ subunits, yet the gene possesses some of the coding capacity for this structure 5′ to its ORF. Although both gpa2 (Gα) and git5 (Gβ) are required for adenylate cyclase activation, only gpa2 is needed to maintain basal cAMP levels. Strains bearing a git5 disruption are derepressed for fbp1 transcription and sexual development even while growing in a glucose-rich environment, although fbp1 derepression is half that observed in gpa2 deletion strains. Multicopy gpa2 partially suppresses the loss of git5, while the converse is not true. These data suggest that Gβ is required for activation of adenylate cyclase either by promoting the activation of Gα or by independently activating adenylate cyclase subsequent to Gα stimulation as seen in type II mammalian adenylate cyclase activation.

scholarly journals Fission Yeast Ste9, a Homolog of Hct1/Cdh1 and Fizzy-related, Is a Novel Negative Regulator of Cell Cycle Progression during G1-Phase

1998 ◽  
Vol 9 (5) ◽  
pp. 1065-1080 ◽  
Author(s):  
Kenji Kitamura ◽  
Hiromi Maekawa ◽  
Chikashi Shimoda
Keyword(s):  
Cell Cycle ◽  
Cell Cycle Arrest ◽  
Fission Yeast ◽  
Cell Cycle Progression ◽  
Negative Regulator ◽  
Yeast Cells ◽  
Restrictive Temperature ◽  
Cycle Progression ◽  
Cycle Arrest ◽  
Mitotic Cyclin

When proliferating fission yeast cells are exposed to nitrogen starvation, they initiate conjugation and differentiate into ascospores. Cell cycle arrest in the G1-phase is one of the prerequisites for cell differentiation, because conjugation occurs only in the pre-Start G1-phase. The role ofste9 + in the cell cycle progression was investigated. Ste9 is a WD-repeat protein that is highly homologous to Hct1/Cdh1 and Fizzy-related. The ste9 mutants were sterile because they were defective in cell cycle arrest in the G1-phase upon starvation. Sterility was partially suppressed by the mutation in cig2 that encoded the major G1/S cyclin. Although cells lacking Ste9 function grow normally, the ste9 mutation was synthetically lethal with the wee1 mutation. In the double mutants ofste9 cdc10 ts, cells arrested in G1-phase at the restrictive temperature, but the level of mitotic cyclin (Cdc13) did not decrease. In these cells, abortive mitosis occurred from the pre-Start G1-phase. Overexpression of Ste9 decreased the Cdc13 protein level and the H1-histone kinase activity. In these cells, mitosis was inhibited and an extra round of DNA replication occurred. Ste9 regulates G1 progression possibly by controlling the amount of the mitotic cyclin in the G1-phase.

scholarly journals Rga6 is a fission yeast Rho GAP involved in Cdc42 regulation of polarized growth

2016 ◽  
Vol 27 (9) ◽  
pp. 1524-1535 ◽  
Author(s):  
M. T. Revilla-Guarinos ◽  
Rebeca Martín-García ◽  
M. Antonia Villar-Tajadura ◽  
Miguel Estravís ◽  
Pedro M. Coll ◽  
...  
Keyword(s):  
Fission Yeast ◽  
Negative Regulator ◽  
Polarized Growth ◽  
Spatial Regulation ◽  
Gtpase Activating Proteins ◽  
C Terminus ◽  
Gfp Fluorescence ◽  
Cell Dimensions ◽  
Actin Cables ◽  
Spatial Specificity

Active Cdc42 is essential for the establishment of polarized growth. This GTPase is negatively regulated by the GTPase-activating proteins (GAPs), which are important for the spatial specificity of Cdc42 function. Rga4 is the only GAP described as negative regulator of fission yeast Cdc42. We report here that Rga6, another fission yeast Cdc42 GAP, shares some functions with Rga4. Cells lacking Rga6 are viable but slightly shorter and broader than wild type, and cells lacking Rga6 and Rga4 simultaneously are rounded. In these cells, active Cdc42 is observed all around the membrane. These additive effects indicate that both GAPs collaborate in the spatial regulation of active Cdc42. Rga6 localizes to the plasma membrane, forming clusters different from those formed by Rga4. A polybasic region at the Rga6 C-terminus is responsible for its membrane localization. Rga6-GFP fluorescence decreases considerably at the growing tips, and this decrease is dependent on the actin cables. Of note, in the absence of Rga6, the amplitude of active Cdc42 oscillations at the tips decreases, and less GTP-Cdc42 accumulates at the new end of the cells. We propose that Rga6 collaborates with Rga4 to spatially restrict active Cdc42 at the cell tips and maintain cell dimensions.

scholarly journals MUTANTS AFFECTED IN ALKALINE PHOSPHATASE EXPRESSION: EVIDENCE FOR MULTIPLE POSITIVE REGULATORS OF THE PHOSPHATE REGULON IN ESCHERICHIA COLI

Genetics ◽  
1980 ◽  
Vol 96 (2) ◽  
pp. 353-366
Author(s):  
Barry L Wanner ◽  
Patrick Latterell
Keyword(s):  
Escherichia Coli ◽  
Alkaline Phosphatase ◽  
Gene Product ◽  
Positive Control ◽  
Negative Control ◽  
Negative Regulator ◽  
Gene Expressions ◽  
Positive Regulators ◽  
New Gene ◽  
Expression Evidence

ABSTRACT The expression of alkaline phosphatase (the product of the phoA gene) in Escherichia coli is believed to be subject to both positive control by the phoB gene product and negative control by the phoR gene product. We have isolated a large number of PhoA- mutants in the phoR  - genetic background. Among mutants altered in the positive control of alkaline phosphatase, some were phoB mutants; others had a mutation in a new gene, designated phoM. We believe that the phoM gene codes for a positive regulator that acts together with the phoB gene product in phoA gene expressions.—The PhoM phenotype was found to be masked in phoR  + strains. This and other evidence support a positive regulatory role for the phoR gene product as well.—Our experiments demonstrate that phoA is under positive control by three different positive regulators: the products of the phoB, phoM and phoR genes. The phoB gene product is always needed together with either the phoR or phoM gene product. In addition, the phoR gene product acts as a negative regulator.—We describe a model for phoA gene expression consistent with this new evidence.

scholarly journals Atf1 Is a Target of the Mitogen-activated Protein Kinase Pmk1 and Regulates Cell Integrity in Fission Yeast

2007 ◽  
Vol 18 (12) ◽  
pp. 4794-4802 ◽  
Author(s):  
Hirofumi Takada ◽  
Masayuki Nishimura ◽  
Yuta Asayama ◽  
Yoshiaki Mannse ◽  
Shunji Ishiwata ◽  
...  
Keyword(s):  
Protein Kinase ◽  
Fission Yeast ◽  
Mapk Pathway ◽  
Mapk Signaling ◽  
Negative Regulator ◽  
Mitogen Activated Protein Kinase ◽  
Mrna Levels ◽  
Cell Integrity ◽  
Dual Specificity ◽  
Mitogen Activated Protein

In fission yeast, knockout of the calcineurin gene resulted in hypersensitivity to Cl−, and the overexpression of pmp1+ encoding a dual-specificity phosphatase for Pmk1 mitogen-activated protein kinase (MAPK) or the knockout of the components of the Pmk1 pathway complemented the Cl− hypersensitivity of calcineurin deletion. Here, we showed that the overexpression of ptc1+ and ptc3+, both encoding type 2C protein phosphatase (PP2C), previously known to inactivate the Wis1–Spc1–Atf1 stress-activated MAPK signaling pathway, suppressed the Cl− hypersensitivity of calcineurin deletion. We also demonstrated that the mRNA levels of these two PP2Cs and pyp2+, another negative regulator of Spc1, are dependent on Pmk1. Notably, the deletion of Atf1, but not that of Spc1, displayed hypersensitivity to the cell wall-damaging agents and also suppressed the Cl− hypersensitivity of calcineurin deletion, both of which are characteristic phenotypes shared by the mutation of the components of the Pmk1 MAPK pathway. Moreover, micafungin treatment induced Pmk1 hyperactivation that resulted in Atf1 hyperphosphorylation. Together, our results suggest that PP2C is involved in a negative feedback loop of the Pmk1 signaling, and results also demonstrate that Atf1 is a key component of the cell integrity signaling downstream of Pmk1 MAPK.

Rapid and reliable preparation of total cell lysates from fission yeast

2006 ◽  
Author(s):  
Atsuko Shirai ◽  
Akihisa Matsuyama ◽  
Yoko Yashiroda ◽  
Ritsuko Arai ◽  
Minoru Yoshida
Keyword(s):  
Fission Yeast ◽  
Total Cell ◽  
Cell Lysates

ERbeta is a negative regulator of the PPARgamma in vivo

2007 ◽  
Vol 2 (S 1) ◽  
Author(s):  
A Foryst-Ludwig ◽  
M Clemenz ◽  
S Hohmann ◽  
C Sprang ◽  
N Frost ◽  
...  
Keyword(s):  
Negative Regulator
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