The UV Response in Saccharomyces cerevisiae Involves the Mitogen-Activated Protein Kinase Slt2p

2004 ◽  
Vol 49 (1) ◽  
Author(s):  
Brad A. Bryan ◽  
Gwendowlyn S. Knapp ◽  
Lori M. Bowen ◽  
Michael Polymenis
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Protein Kinase ◽  
Mitogen Activated Protein Kinase ◽  
Mitogen Activated Protein ◽  
Uv Response

scholarly journals Saccharomyces cerevisiae and Caffeine Implications on the Eukaryotic Cell

Nutrients ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 2440
Author(s):  
Lavinia Liliana Ruta ◽  
Ileana Cornelia Farcasanu
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Protein Kinase ◽  
Molecular Mechanisms ◽  
Eukaryotic Cell ◽  
Pleiotropic Effect ◽  
Mitogen Activated Protein Kinase ◽  
Active Principle ◽  
Cell Integrity ◽  
Tor Signaling ◽  
Mitogen Activated Protein

Caffeine–a methylxanthine analogue of the purine bases adenine and guanine–is by far the most consumed neuro-stimulant, being the active principle of widely consumed beverages such as coffee, tea, hot chocolate, and cola. While the best-known action of caffeine is to prevent sleepiness by blocking the adenosine receptors, caffeine exerts a pleiotropic effect on cells, which lead to the activation or inhibition of various cell integrity pathways. The aim of this review is to present the main studies set to investigate the effects of caffeine on cells using the model eukaryotic microorganism Saccharomyces cerevisiae, highlighting the caffeine synergy with external cell stressors, such as irradiation or exposure to various chemical hazards, including cigarette smoke or chemical carcinogens. The review also focuses on the importance of caffeine-related yeast phenotypes used to resolve molecular mechanisms involved in cell signaling through conserved pathways, such as target of rapamycin (TOR) signaling, Pkc1-Mpk1 mitogen activated protein kinase (MAPK) cascade, or Ras/cAMP protein kinase A (PKA) pathway.

scholarly journals Different polarisome components play distinct roles in Slt2p-regulated cortical ER inheritance in Saccharomyces cerevisiae

2013 ◽  
Vol 24 (19) ◽  
pp. 3145-3154 ◽  
Author(s):  
Xia Li ◽  
Susan Ferro-Novick ◽  
Peter Novick
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Endoplasmic Reticulum ◽  
Cell Wall ◽  
Protein Kinase ◽  
Protein Phosphatase ◽  
Mitogen Activated Protein Kinase ◽  
Common Mechanism ◽  
Late Step ◽  
Mitogen Activated Protein ◽  
Cortical Endoplasmic Reticulum

Ptc1p, a type 2C protein phosphatase, is required for a late step in cortical endoplasmic reticulum (cER) inheritance in Saccharomyces cerevisiae. In ptc1Δ cells, ER tubules migrate from the mother cell and contact the bud tip, yet fail to spread around the bud cortex. This defect results from the failure to inactivate a bud tip–associated pool of the cell wall integrity mitogen-activated protein kinase, Slt2p. Here we report that the polarisome complex affects cER inheritance through its effects on Slt2p, with different components playing distinct roles: Spa2p and Pea2p are required for Slt2p retention at the bud tip, whereas Bni1p, Bud6p, and Sph1p affect the level of Slt2p activation. Depolymerization of actin relieves the ptc1Δ cER inheritance defect, suggesting that in this mutant the ER becomes trapped on the cytoskeleton. Loss of Sec3p also blocks ER inheritance, and, as in ptc1Δ cells, this block is accompanied by activation of Slt2p and is reversed by depolymerization of actin. Our results point to a common mechanism for the regulation of ER inheritance in which Slt2p activity at the bud tip controls the association of the ER with the actin-based cytoskeleton.

scholarly journals Characterization of a serum response factor-like protein in Saccharomyces cerevisiae, Rlm1, which has transcriptional activity regulated by the Mpk1 (Slt2) mitogen-activated protein kinase pathway.

1997 ◽  
Vol 17 (5) ◽  
pp. 2615-2623 ◽  
Author(s):  
Y Watanabe ◽  
G Takaesu ◽  
M Hagiwara ◽  
K Irie ◽  
K Matsumoto
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Protein Kinase ◽  
Map Kinase ◽  
Transcriptional Activation ◽  
Transcriptional Activity ◽  
Mitogen Activated Protein Kinase ◽  
Dependent Manner ◽  
Mads Box ◽  
Mitogen Activated Protein

The Mpk1 (Slt2) mitogen-activated protein (MAP) kinase has been implicated in several biological processes in Saccharomyces cerevisiae. The Rlm1 protein, a member of the MADS box family of transcription factors, functions downstream of Mpk1 in the pathway. To characterize the role of Rlm1 in mediating the transcriptional activation by the Mpk1 pathway, we constructed a LexA-Rlm1 deltaN chimera in which sequences, including the MADS box domain of the Rlm1 protein, were replaced by the LexA DNA binding domain and tested the ability of this chimera to activate a LexA operator-controlled reporter gene. In this assay, the Rlm1 protein was found to activate transcription in a manner regulated by the Mpk1 pathway. The Mpk1 protein kinase phosphorylated Rlm1 deltaN in vitro and the LexA-Rlm1 deltaN chimera protein was phosphorylated in vivo in a Mpk1-dependent manner. These results suggest that Mpk1 regulates the transcriptional activity of Rlm1 by directly phosphorylating it. We identified a Mpk1-like protein kinase, Mlp1, as an Rlm1-associated protein by using the yeast two-hybrid system. Overexpression of MLP1 suppresses the caffeine-sensitive phenotype of the bck1 delta mutation. The additivity of the mlp1 delta defect with the Mpk1 delta defect with regard to the caffeine sensitivity, combined with the results of genetic epistasis experiments, suggested that the activity of Rlm1 is regulated independently by Mpk1 MAP kinase and the Mlp1 MAP kinase-like kinase.

scholarly journals Effect of the Pheromone-Responsive Gα and Phosphatase Proteins of Saccharomyces cerevisiae on the Subcellular Localization of the Fus3 Mitogen-Activated Protein Kinase

2003 ◽  
Vol 23 (4) ◽  
pp. 1135-1150 ◽  
Author(s):  
Ernest Blackwell ◽  
Izabel M. Halatek ◽  
Hye-Jin N. Kim ◽  
Alexis T. Ellicott ◽  
Andrey A. Obukhov ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Protein Kinase ◽  
Fluorescent Protein ◽  
Nucleocytoplasmic Transport ◽  
Mitogen Activated Protein Kinase ◽  
Mutant Form ◽  
Relative Level ◽  
Mitogen Activated Protein ◽  
Mating Signal ◽  
Green Fluorescent

ABSTRACT The mating-specific Gα protein of Saccharomyces cerevisiae, Gpa1, stimulates adaptation to pheromone by a mechanism independent of Gβγ sequestration. Genetic evidence suggests that Gpa1 targets the Fus3 mitogen-activated protein kinase, and it has recently been shown that the two proteins interact in cells responding to pheromone. To test the possibility that Gpa1 downregulates the mating signal by affecting the localization of Fus3, we created a Fus3-green fluorescent protein (GFP) fusion protein. In vegetative cells, Fus3-GFP was found in both the cytoplasm and the nucleus. Pheromone stimulated a measurable increase in the ratio of nuclear to cytoplasmic Fus3-GFP. In contrast, the relative level of nuclear Fus3-GFP decreased as cells recovered from pheromone arrest and did not increase when cells adapted to chronic stimulus were challenged again. Accumulation of Fus3-GFP in the nuclei of stimulated cells was also inhibited by overexpression of either wild-type Gpa1, the E364K hyperadaptive mutant form of Gpa1, or the Msg5 dually specific phosphatase. The effects of Gpa1 and Msg5 on Fus3 are partially interdependent. In a genetic screen for adaptive defective mutants, a nonsense allele of the nucleocytoplasmic transport receptor, Kap104, was identified. Truncation of the Kap104 cargo-binding domain blocked the effect of both Gpa1E364K and Msg5 on Fus3-GFP localization. Based on these results, we propose that Gpa1 and Msg5 work in concert to downregulate the mating signal and that they do so by inhibiting the pheromone-induced increase of Fus3 in the nucleus. Kap104 is required for the Gα/phosphatase-mediated effect on Fus3 localization.

scholarly journals Regulation of the Saccharomyces cerevisiae HOG1 mitogen-activated protein kinase by the PTP2 and PTP3 protein tyrosine phosphatases.

1997 ◽  
Vol 17 (3) ◽  
pp. 1289-1297 ◽  
Author(s):  
S M Wurgler-Murphy ◽  
T Maeda ◽  
E A Witten ◽  
H Saito
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Protein Kinase ◽  
Protein Tyrosine Phosphatase ◽  
Tyrosine Phosphatase ◽  
Mitogen Activated Protein Kinase ◽  
Yeast Cells ◽  
High Osmolarity ◽  
Mapk Kinase ◽  
Protein Tyrosine ◽  
Mitogen Activated Protein

In response to increases in extracellular osmolarity, Saccharomyces cerevisiae activates the HOG1 mitogen-activated protein kinase (MAPK) cascade, which is composed of a pair of redundant MAPK kinase kinases, namely, Ssk2p and Ssk22p, the MAPK kinase Pbs2p, and the MAPK Hog1p. Hog1p is activated by Pbs2p through phosphorylation of specific threonine and tyrosine residues. Activated Hog1p is essential for survival of yeast cells at high osmolarity. However, expression of constitutively active mutant kinases, such as those encoded by SSK2deltaN and PBS2(DD), is toxic and results in a lethal level of Hog1p activation. Overexpression of the protein tyrosine phosphatase Ptp2p suppresses the lethality of these mutations by dephosphorylating Hog1p. A catalytically inactive Cys-to-Ser Ptp2p mutant (Ptp2(C/S)p) is tightly bound to tyrosine-phosphorylated Hog1p in vivo. Disruption of PTP2 leads to elevated levels of tyrosine-phosphorylated Hog1p following exposure of cells to high osmolarity. Disruption of both PTP2 and another protein tyrosine phosphatase gene, PTP3, results in constitutive Hog1p tyrosine phosphorylation even in the absence of increased osmolarity. Thus, Ptp2p and Ptp3p are the major phosphatases responsible for the tyrosine dephosphorylation of Hog1p. When catalytically inactive Hog1(K/N)p is expressed in hog1delta cells, it is constitutively tyrosine phosphorylated. In contrast, Hog1(K/N)p, expressed together with wild-type Hog1p, is tyrosine phosphorylated only when cells are exposed to high osmolarity. Thus, the kinase activity of Hog1p is required for its own tyrosine dephosphorylation. Northern blot analyses suggest that Hog1p regulates Ptp2p and/or Ptp3p activity at the posttranscriptional level.

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