Ask10p Mediates the Oxidative Stress-Induced Destruction of the Saccharomyces cerevisiae C-Type Cyclin Ume3p/Srb11p

ABSTRACT Srb11p-Srb10p is the budding yeast C-type cyclin-cyclin-dependent kinase that is required for the repression of several stress response genes. To relieve this repression, Srb11p is destroyed in cells exposed to stressors, including heat shock and oxidative stress. In the present study, we identified Ask10p (for activator of Skn7) by two-hybrid analysis as an interactor with Srb11p. Coimmunoprecipitation studies confirmed this association, and we found that, similar to Srb11p-Srb10p, Ask10p is a component of the RNA polymerase II holoenzyme. Ask10p is required for Srb11p destruction in response to oxidative stress but not heat shock. Moreover, this destruction is important since the hypersensitivity of an ask10 mutant strain to oxidative stress is rescued by deleting SRB11. We further show that Ask10p is phosphorylated in response to oxidative stress but not heat shock. This modification requires the redundant mitogen-activated protein (MAP) kinase kinase Mkk1/2 but not their normal MAP kinase target Slt2p. Moreover, the other vegetative MAP kinases—Hog1p, Fus3p, or Kss1p—are not required for Ask10p phosphorylation, suggesting the existence of an alternative pathway for transducing the Pkc1p→Bck1→Mkk1/2 oxidative stress signal. In conclusion, Ask10p is a new component of the RNA polymerase II holoenzyme and an important regulator of the oxidative stress response. In addition, these results define a new role for the Pkc1p MAP kinase cascade (except the MAP kinase itself) in transducing the oxidative damage signal directly to the RNA polymerase II holoenzyme, thereby bypassing the stress-activated transcription factors.

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Phosphorylation of the 27-kDa heat shock protein via p38 MAP kinase and MAPKAP kinase in smooth muscle

AJP Lung Cellular and Molecular Physiology ◽

10.1152/ajplung.1997.273.5.l930 ◽

1997 ◽

Vol 273 (5) ◽

pp. L930-L940 ◽

Cited By ~ 37

Author(s):

Janice K. Larsen ◽

Ilia A. Yamboliev ◽

Lee A. Weber ◽

William T. Gerthoffer

Keyword(s):

Smooth Muscle ◽

Stress Response ◽

Heat Shock ◽

Heat Shock Protein ◽

Map Kinase ◽

Tyrosine Phosphorylation ◽

Airway Smooth Muscle ◽

Muscarinic Receptors ◽

P38 Map Kinase ◽

Mitogen Activated Protein

The 27-kDa heat shock protein (HSP27) is expressed in a variety of tissues in the absence of stress and is thought to regulate actin filament dynamics, possibly by a phosphorylation/dephosphorylation mechanism. HSP27 has also been suggested to be involved in contraction of intestinal smooth muscle. We have investigated phosphorylation of HSP27 in airway smooth muscle in response to the muscarinic agonist carbachol. Carbachol increased32P incorporation into canine tracheal HSP27 and induced a shift in the distribution of charge isoforms on two-dimensional gels to more acidic, phosphorylated forms. The canine HSP27 amino acid sequence includes three serine residues corresponding to sites in human HSP27 known to be phosphorylated by mitogen-activated protein kinase-activated protein (MAPKAP) kinase-2. To determine whether muscarinic receptors are coupled to a “stress response” pathway in smooth muscle culminating in phosphorylation of HSP27, we assayed MAPKAP kinase-2 activity and tyrosine phosphorylation of p38 mitogen-activated protein (MAP) kinase, the enzyme thought to activate MAPKAP kinase-2. Recombinant canine HSP27 expressed in Escherichia coli was a substrate for MAPKAP kinase-2 in vitro as well as a substrate for endogenous smooth muscle HSP27 kinase, which was activated by carbachol. Carbachol also increased tyrosine phosphorylation of p38 MAP kinase. SB-203580, an inhibitor of p38 MAP kinases, reduced activation of endogenous HSP27 kinase activity and blocked the shift in HSP27 charge isoforms to acidic forms. We suggest that HSP27 in airway smooth muscle, in addition to being a stress response protein, is phosphorylated by a receptor-initiated signaling cascade involving muscarinic receptors, tyrosine phosphorylation of p38 MAP kinase, and activation of MAPKAP kinase-2.

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Phosphorylation State of the RNA Polymerase II C-Terminal Domain (CTD) in Heat-Shocked Cells. Possible Involvement of the Stress-Activated Mitogen-Activated Protein (MAP) Kinases

European Journal of Biochemistry ◽

10.1111/j.1432-1033.1995.083_1.x ◽

1995 ◽

Vol 233 (1) ◽

pp. 83-92 ◽

Cited By ~ 29

Author(s):

Aniko Venetianer ◽

Marie-Francoise Dubois ◽

Van Trung Nguyen ◽

Sylvain Bellier ◽

Sook-Jae Seo ◽

...

Keyword(s):

Rna Polymerase ◽

Rna Polymerase Ii ◽

Map Kinases ◽

Phosphorylation State ◽

Terminal Domain ◽

Protein Map ◽

Mitogen Activated Protein

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Activation of mitogen-activated protein kinase by heat shock treatment in Drosophila

Biochemical Journal ◽

10.1042/bj3120341 ◽

1995 ◽

Vol 312 (2) ◽

pp. 341-349 ◽

Cited By ~ 11

Author(s):

F Chen ◽

M Torres ◽

R F Duncan

Keyword(s):

Heat Shock ◽

Map Kinase ◽

Tyrosine Phosphorylation ◽

Map Kinases ◽

Early Response ◽

Shock Treatment ◽

Mitogen Activated Protein Kinase ◽

Heat Shock Treatment ◽

Kinase Activation ◽

Mitogen Activated Protein

Heat shock treatment of Drosophila melanogaster tissue culture cells causes increased tyrosine phosphorylation of several 44 kDa proteins, which are identified as Drosophila mitogen-activated protein (MAP) kinases. Tyrosine phosphorylation occurs within 5 min, and is maintained at high levels during heat shock. It decreases to basal levels during recovery, concurrent with the repression of heat shock transcription and heat-shock-protein synthesis. The increased MAP kinase tyrosine phosphorylation is parallelled by increased MAP kinase activity. At least two MAP kinases, DmERK-A and DmERK-B, are identified whose tyrosine phosphorylation increases during heat shock. Thus MAP kinase activation is an immediate early response to heat shock, and its increased activity is maintained throughout heat shock treatment. Protracted MAP kinase activation may contribute to heat shock transcription factor phosphorylation and the numerous metabolic alterations that constitute the heat-shock response.

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Phosphorylation of the RNA polymerase II largest subunit during Xenopus laevis oocyte maturation.

Molecular and Cellular Biology ◽

10.1128/mcb.17.3.1434 ◽

1997 ◽

Vol 17 (3) ◽

pp. 1434-1440 ◽

Cited By ~ 43

Author(s):

S Bellier ◽

M F Dubois ◽

E Nishida ◽

G Almouzni ◽

O Bensaude

Keyword(s):

Xenopus Laevis ◽

Rna Polymerase ◽

Map Kinase ◽

Rna Polymerase Ii ◽

Oocyte Maturation ◽

Mammalian Cells ◽

Map Kinases ◽

Kinase Activity ◽

Cyclin B1 ◽

Xenopus Laevis Oocyte

Xenopus laevis oogenesis is characterized by an active transcription which ceases abruptly upon maturation. To survey changes in the characteristics of the transcriptional machinery which might contribute to this transcriptional arrest, the phosphorylation status of the RNA polymerase II largest subunit (RPB1 subunit) was analyzed during oocyte maturation. We found that the RPB1 subunit accumulates in large quantities from previtellogenic early diplotene oocytes up to fully grown oocytes. The C-terminal domain (CTD) of the RPB1 subunit was essentially hypophosphorylated in growing oocytes from Dumont stage IV to stage VI. Upon maturation, the proportion of hyperphosphorylated RPB1 subunits increased dramatically and abruptly. The hyperphosphorylated RPB1 subunits were dephosphorylated within 1 h after fertilization or heat shock of the matured oocytes. Extracts from metaphase II-arrested oocytes showed a much stronger CTD kinase activity than extracts from prophase stage VI oocytes. Most of this kinase activity was attributed to the activated Xp42 mitogen-activated protein (MAP) kinase, a MAP kinase of the ERK type. Making use of artificial maturation of the stage VI oocyte through microinjection of a recombinant stable cyclin B1, we observed a parallel activation of Xp42 MAP kinase and phosphorylation of RPB1. Both events required protein synthesis, which demonstrated that activation of p34(cdc2)off kinase was insufficient to phosphorylate RPB1 ex vivo and was consistent with a contribution of the Xp42 MAP kinase to RPB1 subunit phosphorylation. These results further support the possibility that the largest RNA polymerase II subunit is a substrate of the ERK-type MAP kinases during oocyte maturation, as previously proposed during stress or growth factor stimulation of mammalian cells.

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The Hog1 Mitogen-Activated Protein Kinase Is Essential in the Oxidative Stress Response and Chlamydospore Formation in Candidaalbicans

Eukaryotic Cell ◽

10.1128/ec.2.2.351-361.2003 ◽

2003 ◽

Vol 2 (2) ◽

pp. 351-361 ◽

Cited By ~ 224

Author(s):

Rebeca Alonso-Monge ◽

Federico Navarro-García ◽

Elvira Román ◽

Ana I. Negredo ◽

Blanca Eisman ◽

...

Keyword(s):

Oxidative Stress ◽

Hydrogen Peroxide ◽

Stress Response ◽

Map Kinase ◽

Uv Light ◽

Molecular Model ◽

Oxidative Stress Response ◽

Mitogen Activated Protein Kinase ◽

Chlamydospore Formation ◽

Mitogen Activated Protein

ABSTRACT Candida albicans mutants with mutations in mitogen-activated protein (MAP) kinase HOG1 displayed an increased sensitivity to agents producing reactive oxygen species, such as oxidants (menadione, hydrogen peroxide, or potassium superoxide), and UV light. Consistent with this finding, C. albicans Hog1 was activated not only in response to an increase in external osmolarity, as happens with its Saccharomyces cerevisiae homologue, but also in response to hydrogen peroxide. The Hog1-mediated response to oxidative stress was different from that of transcription factor Cap1, the homologue of S. cerevisiae Yap1, as shown by the different sensitivities to oxidants and the kinetics of cell death of cap1Δ, hog1, and hog1 cap1Δ mutants. Deletion of CAP1 did not influence the level of Hog1 phosphorylation, and deletion of HOG1 did not affect Cap1 nuclear localization. Moreover, we show that the HOG1 gene plays a role in chlamydospore formation, another oxygen-related morphogenetic event, as demonstrated by the fact that hog1 cells were unable to generate these thick-walled structures in several media through a mechanism different from that of the EFG1 regulator. This is the first demonstration of the role of the Hog1-mediated MAP kinase pathway in resistance to oxidative stress in pathogenic fungi, and it allows us to propose a molecular model for the oxidative stress response in C. albicans.

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Faculty Opinions recommendation of Structure of the yeast RNA polymerase II holoenzyme: Mediator conformation and polymerase interaction.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.1009586.130061 ◽

2002 ◽

Author(s):

Michael Meisterernst

Keyword(s):

Rna Polymerase ◽

Rna Polymerase Ii ◽

Rna Polymerase Ii Holoenzyme

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Faculty Opinions recommendation of Fcp1 dephosphorylation of the RNA polymerase II C-terminal domain is required for efficient transcription of heat shock genes.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.717953280.793458855 ◽

2012 ◽

Author(s):

Robert P Fisher

Keyword(s):

Heat Shock ◽

Rna Polymerase ◽

Rna Polymerase Ii ◽

Heat Shock Genes ◽

Terminal Domain

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The rye Mutants Identify a Role for Ssn/Srb Proteins of the RNA Polymerase II Holoenzyme During Stationary Phase Entry in Saccharomyces cerevisiae

Genetics ◽

10.1093/genetics/157.1.17 ◽

2001 ◽

Vol 157 (1) ◽

pp. 17-26 ◽

Cited By ~ 3

Author(s):

Ya-Wen Chang ◽

Susie C Howard ◽

Yelena V Budovskaya ◽

Jasper Rine ◽

Paul K Herman

Keyword(s):

Saccharomyces Cerevisiae ◽

Cell Growth ◽

Rna Polymerase ◽

Stationary Phase ◽

Yeast Cell ◽

Rna Polymerase Ii ◽

Transcriptional Response ◽

Nutrient Deprivation ◽

Ras Signaling ◽

Rna Polymerase Ii Holoenzyme

Abstract Saccharomyces cerevisiae cells enter into a distinct resting state, known as stationary phase, in response to specific types of nutrient deprivation. We have identified a collection of mutants that exhibited a defective transcriptional response to nutrient limitation and failed to enter into a normal stationary phase. These rye mutants were isolated on the basis of defects in the regulation of YGP1 expression. In wild-type cells, YGP1 levels increased during the growth arrest caused by nutrient deprivation or inactivation of the Ras signaling pathway. In contrast, the levels of YGP1 and related genes were significantly elevated in the rye mutants during log phase growth. The rye defects were not specific to this YGP1 response as these mutants also exhibited multiple defects in stationary phase properties, including an inability to survive periods of prolonged starvation. These data indicated that the RYE genes might encode important regulators of yeast cell growth. Interestingly, three of the RYE genes encoded the Ssn/Srb proteins, Srb9p, Srb10p, and Srb11p, which are associated with the RNA polymerase II holoenzyme. Thus, the RNA polymerase II holoenzyme may be a target of the signaling pathways responsible for coordinating yeast cell growth with nutrient availability.

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