scholarly journals Role of Cdc42-Cla4 Interaction in the Pheromone Response of Saccharomyces cerevisiae

2006 ◽  
Vol 6 (2) ◽  
pp. 317-327 ◽  
Author(s):  
Melanie Heinrich ◽  
Tim Köhler ◽  
Hans-Ulrich Mösch
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Cell Cycle ◽  
Map Kinase ◽  
Cell Cycle Arrest ◽  
Map Kinases ◽  
Negative Regulator ◽  
Cycle Arrest ◽  
Mitogen Activated Protein ◽  
Novel Alleles

ABSTRACT In Saccharomyces cerevisiae, the highly conserved Rho-type GTPase Cdc42 is essential for cell division and controls cellular development during mating and invasive growth. The role of Cdc42 in mating has been controversial, but a number of previous studies suggest that the GTPase controls the mitogen-activated protein (MAP) kinase cascade by activating the p21-activated protein kinase (PAK) Ste20. To further explore the role of Cdc42 in pheromone-stimulated signaling, we isolated novel alleles of CDC42 that confer resistance to pheromone. We find that in CDC42(V36A) and CDC42(V36A, I182T) mutant strains, the inability to undergo pheromone-induced cell cycle arrest correlates with reduced phosphorylation of the mating MAP kinases Fus3 and Kss1 and with a decrease in mating efficiency. Furthermore, Cdc42(V36A) and Cdc42(V36A, I182T) proteins show reduced interaction with the PAK Cla4 but not with Ste20. We also show that deletion of CLA4 in a CDC42(V36A, I182T) mutant strain suppresses pheromone resistance and that overexpression of CLA4 interferes with pheromone-induced cell cycle arrest and MAP kinase phosphorylation in CDC42 wild-type strains. Our data indicate that Cla4 has the potential to act as a negative regulator of the mating pathway and that this function of the PAK might be under control of Cdc42. In conclusion, our study suggests that control of pheromone signaling by Cdc42 not only depends on Ste20 but also involves interaction of the GTPase with Cla4.

scholarly journals Mitogen-Activated Protein Kinase Hog1 Mediates Adaptation to G1 Checkpoint Arrest during Arsenite and Hyperosmotic Stress

2008 ◽  
Vol 7 (8) ◽  
pp. 1309-1317 ◽  
Author(s):  
Iwona Migdal ◽  
Yulia Ilina ◽  
Markus J. Tamás ◽  
Robert Wysocki
Keyword(s):  
Cell Cycle ◽  
Protein Kinase ◽  
Cell Cycle Arrest ◽  
Kinase Inhibitor ◽  
Hyperosmotic Stress ◽  
Mitogen Activated Protein Kinase ◽  
Hog Pathway ◽  
Cycle Arrest ◽  
Mitogen Activated Protein

ABSTRACT Cells slow down cell cycle progression in order to adapt to unfavorable stress conditions. Yeast (Saccharomyces cerevisiae) responds to osmotic stress by triggering G1 and G2 checkpoint delays that are dependent on the mitogen-activated protein kinase (MAPK) Hog1. The high-osmolarity glycerol (HOG) pathway is also activated by arsenite, and the hog1Δ mutant is highly sensitive to arsenite, partly due to increased arsenite influx into hog1Δ cells. Yeast cell cycle regulation in response to arsenite and the role of Hog1 in this process have not yet been analyzed. Here, we found that long-term exposure to arsenite led to transient G1 and G2 delays in wild-type cells, whereas cells that lack the HOG1 gene or are defective in Hog1 kinase activity displayed persistent G1 cell cycle arrest. Elevated levels of intracellular arsenite and “cross talk” between the HOG and pheromone response pathways, observed in arsenite-treated hog1Δ cells, prolonged the G1 delay but did not cause a persistent G1 arrest. In contrast, deletion of the SIC1 gene encoding a cyclin-dependent kinase inhibitor fully suppressed the observed block of G1 exit in hog1Δ cells. Moreover, the Sic1 protein was stabilized in arsenite-treated hog1Δ cells. Interestingly, Sic1-dependent persistent G1 arrest was also observed in hog1Δ cells during hyperosmotic stress. Taken together, our data point to an important role of the Hog1 kinase in adaptation to stress-induced G1 cell cycle arrest.

scholarly journals Oncogenic ras and p53 Cooperate To Induce Cellular Senescence

2002 ◽  
Vol 22 (10) ◽  
pp. 3497-3508 ◽  
Author(s):  
Gerardo Ferbeyre ◽  
Elisa de Stanchina ◽  
Athena W. Lin ◽  
Emmanuelle Querido ◽  
Mila E. McCurrach ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Map Kinase ◽  
Cell Cycle Arrest ◽  
Cellular Senescence ◽  
Null Mouse ◽  
P53 Expression ◽  
Oncogenic Ras ◽  
Cycle Arrest ◽  
Murine Fibroblasts ◽  
Mitogen Activated Protein

ABSTRACT Oncogenic activation of the mitogen-activated protein (MAP) kinase cascade in murine fibroblasts initiates a senescence-like cell cycle arrest that depends on the ARF/p53 tumor suppressor pathway. To investigate whether p53 is sufficient to induce senescence, we introduced a conditional murine p53 allele (p53val135 ) into p53-null mouse embryonic fibroblasts and examined cell proliferation and senescence in cells expressing p53, oncogenic Ras, or both gene products. Conditional p53 activation efficiently induced a reversible cell cycle arrest but was unable to induce features of senescence. In contrast, coexpression of oncogenic ras or activated mek1 with p53 enhanced both p53 levels and activity relative to that observed for p53 alone and produced an irreversible cell cycle arrest that displayed features of cellular senescence. p19ARF was required for this effect, since p53 −/− ARF −/− double-null cells were unable to undergo senescence following coexpression of oncogenic Ras and p53. Although the levels of exogenous p53 achieved in ARF-null cells were relatively low, the stabilizing effects of p19ARF on p53 could not explain the cooperation between oncogenic Ras and p53 in promoting senescence. Hence, enforced p53 expression without oncogenic ras in p53 −/− mdm2 −/− double-null cells produced extremely high p53 levels but did not induce senescence. Taken together, our results indicate that oncogenic activation of the MAP kinase pathway in murine fibroblasts converts p53 into a senescence inducer through both quantitative and qualitative mechanisms.

Characterization of RAD9 of Saccharomyces cerevisiae and evidence that its function acts posttranslationally in cell cycle arrest after DNA damage

1990 ◽  
Vol 10 (12) ◽  
pp. 6554-6564
Author(s):  
T A Weinert ◽  
L H Hartwell
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Cell Cycle ◽  
Dna Damage ◽  
Cell Cycle Arrest ◽  
Dna Sequence ◽  
Negative Regulator ◽  
Yeast Cells ◽  
Protein Synthesis Inhibitor ◽  
Cycle Arrest ◽  
Delta Cells

In eucaryotic cells, incompletely replicated or damaged chromosomes induce cell cycle arrest in G2 before mitosis, and in the yeast Saccharomyces cerevisiae the RAD9 gene is essential for the cell cycle arrest (T.A. Weinert and L. H. Hartwell, Science 241:317-322, 1988). In this report, we extend the analysis of RAD9-dependent cell cycle control. We found that both induction of RAD9-dependent arrest in G2 and recovery from arrest could occur in the presence of the protein synthesis inhibitor cycloheximide, showing that the mechanism of RAD9-dependent control involves a posttranslational mechanism(s). We have isolated and determined the DNA sequence of the RAD9 gene, confirming the DNA sequence reported previously (R. H. Schiestl, P. Reynolds, S. Prakash, and L. Prakash, Mol. Cell. Biol. 9:1882-1886, 1989). The predicted protein sequence for the Rad9 protein bears no similarity to sequences of known proteins. We also found that synthesis of the RAD9 transcript in the cell cycle was constitutive and not induced by X-irradiation. We constructed yeast cells containing a complete deletion of the RAD9 gene; the rad9 null mutants were viable, sensitive to X- and UV irradiation, and defective for cell cycle arrest after DNA damage. Although Rad+ and rad9 delta cells had similar growth rates and cell cycle kinetics in unirradiated cells, the spontaneous rate of chromosome loss (in unirradiated cells) was elevated 7- to 21-fold in rad9 delta cells. These studies show that in the presence of induced or endogenous DNA damage, RAD9 is a negative regulator that inhibits progression from G2 in order to preserve cell viability and to maintain the fidelity of chromosome transmission.

scholarly journals p38 Mitogen-Activated Protein Kinase- and HuR-Dependent Stabilization of p21Cip1 mRNA Mediates the G1/S Checkpoint

2009 ◽  
Vol 29 (16) ◽  
pp. 4341-4351 ◽  
Author(s):  
Vanesa Lafarga ◽  
Ana Cuadrado ◽  
Isabel Lopez de Silanes ◽  
Rocio Bengoechea ◽  
Oscar Fernandez-Capetillo ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Dna Damage ◽  
Protein Kinase ◽  
Cell Cycle Arrest ◽  
P38 Mapk ◽  
Mitogen Activated Protein Kinase ◽  
Γ Radiation ◽  
Cycle Arrest ◽  
Mitogen Activated Protein

ABSTRACT Activation of p38 mitogen-activated protein kinase (MAPK) plays an important role in the G2/M cell cycle arrest induced by DNA damage, but little is known about the role of this signaling pathway in the G1/S transition. Upregulation of the cyclin-dependent kinase inhibitor p21Cip1 is thought to make a major contribution to the G1/S cell cycle arrest induced by γ radiation. We show here that inhibition of p38 MAPK impairs p21Cip1 accumulation and, as a result, the ability of cells to arrest in G1 in response to γ radiation. We found that p38 MAPK induces p21Cip1 mRNA stabilization, without affecting its transcription or the stability of the protein. In particular, p38 MAPK phosphorylates the mRNA binding protein HuR on Thr118, which results in cytoplasmic accumulation of HuR and its enhanced binding to the p21Cip1 mRNA. Our findings help to understand the emerging role of p38 MAPK in the cellular responses to DNA damage and reveal the existence of p53-independent networks that cooperate in modulating p21Cip1 levels at the G1/S checkpoint.

scholarly journals Cln3-Associated Kinase Activity inSaccharomyces cerevisiae Is Regulated by the Mating Factor Pathway

1998 ◽  
Vol 18 (1) ◽  
pp. 433-441 ◽  
Author(s):  
Doo-Il Jeoung ◽  
L. J. W. M. Oehlen ◽  
Frederick R. Cross
Keyword(s):  
Cell Cycle ◽  
Cell Cycle Arrest ◽  
Map Kinases ◽  
Kinase Activity ◽  
Specific Activity ◽  
Cycle Arrest ◽  
Protein Map ◽  
Mitogen Activated Protein ◽  
Cycle Regulation ◽  
Mating Factor

ABSTRACT The Saccharomyces cerevisiae cell cycle is arrested in G1 phase by the mating factor pathway. Genetic evidence has suggested that the G1 cyclins Cln1, Cln2, and Cln3 are targets of this pathway whose inhibition results in G1 arrest. Inhibition of Cln1- and Cln2-associated kinase activity by the mating factor pathway acting through Far1 has been described. Here we report that Cln3-associated kinase activity is inhibited by mating factor treatment, with dose response and timing consistent with involvement in cell cycle arrest. No regulation of Cln3-associated kinase was observed in a fus3 kss1 strain deficient in mating factor pathway mitogen-activated protein (MAP) kinases. Inhibition occurs mainly at the level of specific activity of Cln3-Cdc28 complexes. Inhibition of the C-terminally truncated Cln3-1-associated kinase is not observed; such truncations were previously identified genetically as causing resistance to mating factor-induced cell cycle arrest. Regulation of Cln3-associated kinase specific activity by mating factor treatment requires Far1. Overexpression of Far1 restores inhibition of C-terminally truncated Cln3-1-associated kinase activity. G2/M-arrested cells are unable to regulate Cln3-associated kinase, possibly because of cell cycle regulation of Far1 abundance. Inhibition of Cln3-associated kinase activity by the mating factor pathway may allow this pathway to block the earliest step in normal cell cycle initiation, since Cln3 functions as the most upstream G1-acting cyclin, activating transcription of the G1 cyclins CLN1 and CLN2 as well as of the S-phase cyclins CLB5 and CLB6.

A RAD9-dependent checkpoint blocks meiosis of cdc13 yeast cells.

Genetics ◽  
1992 ◽  
Vol 131 (1) ◽  
pp. 55-63 ◽  
Author(s):  
L Weber ◽  
B Byers
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Cell Cycle ◽  
Cell Cycle Arrest ◽  
Mitotic Division ◽  
Yeast Cells ◽  
Mitotic Progression ◽  
Meiotic Progression ◽  
Cycle Arrest ◽  
Yeast Meiosis

Abstract Mutations in CDC13 have previously been found to cause cell cycle arrest of Saccharomyces cerevisiae at a stage in G2 immediately preceding the mitotic division. We show here that cdc13 blocks the meiotic pathway at a stage that follows DNA replication, but in this case the spindle has not yet formed nor have the chromosomes undergone synapsis or recombination. This arrest is alleviated by rad9, thus implicating the same checkpoint function that delays mitotic progression when chromosomal lesions are present. An assessment of the spores produced upon alleviation of the meiotic arrest by rad9 reveals that the absence of recombination in strains bearing cdc13 alone is attributable to the RAD9-mediated arrest rather than to other effects of cdc13 lesions. We have tested the possibility that this checkpoint function is important in regulating meiotic progression to permit resolution of recombinational intermediates during ongoing meiosis and have found no evidence that rad9 alters the execution of functions that might depend upon such regulation. We consider the possible role of other checkpoints in yeast meiosis.

scholarly journals Characterization of RAD9 of Saccharomyces cerevisiae and evidence that its function acts posttranslationally in cell cycle arrest after DNA damage.

1990 ◽  
Vol 10 (12) ◽  
pp. 6554-6564 ◽  
Author(s):  
T A Weinert ◽  
L H Hartwell
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Cell Cycle ◽  
Dna Damage ◽  
Cell Cycle Arrest ◽  
Dna Sequence ◽  
Negative Regulator ◽  
Yeast Cells ◽  
Protein Synthesis Inhibitor ◽  
Cycle Arrest ◽  
Delta Cells

In eucaryotic cells, incompletely replicated or damaged chromosomes induce cell cycle arrest in G2 before mitosis, and in the yeast Saccharomyces cerevisiae the RAD9 gene is essential for the cell cycle arrest (T.A. Weinert and L. H. Hartwell, Science 241:317-322, 1988). In this report, we extend the analysis of RAD9-dependent cell cycle control. We found that both induction of RAD9-dependent arrest in G2 and recovery from arrest could occur in the presence of the protein synthesis inhibitor cycloheximide, showing that the mechanism of RAD9-dependent control involves a posttranslational mechanism(s). We have isolated and determined the DNA sequence of the RAD9 gene, confirming the DNA sequence reported previously (R. H. Schiestl, P. Reynolds, S. Prakash, and L. Prakash, Mol. Cell. Biol. 9:1882-1886, 1989). The predicted protein sequence for the Rad9 protein bears no similarity to sequences of known proteins. We also found that synthesis of the RAD9 transcript in the cell cycle was constitutive and not induced by X-irradiation. We constructed yeast cells containing a complete deletion of the RAD9 gene; the rad9 null mutants were viable, sensitive to X- and UV irradiation, and defective for cell cycle arrest after DNA damage. Although Rad+ and rad9 delta cells had similar growth rates and cell cycle kinetics in unirradiated cells, the spontaneous rate of chromosome loss (in unirradiated cells) was elevated 7- to 21-fold in rad9 delta cells. These studies show that in the presence of induced or endogenous DNA damage, RAD9 is a negative regulator that inhibits progression from G2 in order to preserve cell viability and to maintain the fidelity of chromosome transmission.

scholarly journals Role of Mis Localization of DNA Repair Factors in Cell Cycle Arrest

2019 ◽  
Vol 116 (3) ◽  
pp. 76a
Author(s):  
Manasvita Vashisth ◽  
Sangkyun Cho ◽  
Dennis Discher
Keyword(s):  
Cell Cycle ◽  
Dna Repair ◽  
Cell Cycle Arrest ◽  
Cycle Arrest

scholarly journals Cellular Senescence in Liver Disease and Regeneration

2021 ◽  
Author(s):  
Sofia Ferreira-Gonzalez ◽  
Daniel Rodrigo-Torres ◽  
Victoria L. Gadd ◽  
Stuart J. Forbes
Keyword(s):  
Cell Cycle ◽  
Liver Disease ◽  
Cell Cycle Arrest ◽  
Genomic Instability ◽  
Cellular Senescence ◽  
Cell Populations ◽  
Cycle Arrest ◽  
Relevant Role ◽  
Extent Of Damage

AbstractCellular senescence is an irreversible cell cycle arrest implemented by the cell as a result of stressful insults. Characterized by phenotypic alterations, including secretome changes and genomic instability, senescence is capable of exerting both detrimental and beneficial processes. Accumulating evidence has shown that cellular senescence plays a relevant role in the occurrence and development of liver disease, as a mechanism to contain damage and promote regeneration, but also characterizing the onset and correlating with the extent of damage. The evidence of senescent mechanisms acting on the cell populations of the liver will be described including the role of markers to detect cellular senescence. Overall, this review intends to summarize the role of senescence in liver homeostasis, injury, disease, and regeneration.

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