scholarly journals Ineffective Phosphorylation of Mitogen-Activated Protein Kinase Hog1p in Response to High Osmotic Stress in the Yeast Kluyveromyces lactis

2015 ◽  
Vol 14 (9) ◽  
pp. 922-930 ◽  
Author(s):  
Nancy Velázquez-Zavala ◽  
Miriam Rodríguez-González ◽  
Rocío Navarro-Olmos ◽  
Laura Ongay-Larios ◽  
Laura Kawasaki ◽  
...  
Keyword(s):  
Protein Kinase ◽  
Osmotic Stress ◽  
Kluyveromyces Lactis ◽  
Chimeric Protein ◽  
High Sensitivity ◽  
Hyperosmotic Stress ◽  
Mitogen Activated Protein Kinase ◽  
Hog Pathway ◽  
Content Type ◽  
Mitogen Activated Protein

ABSTRACT When treated with a hyperosmotic stimulus, Kluyveromyces lactis cells respond by activating the mitogen-activated protein kinase (MAPK) K. lactis Hog1 (KlHog1) protein via two conserved branches, SLN1 and SHO1. Mutants affected in only one branch can cope with external hyperosmolarity by activating KlHog1p by phosphorylation, except for single Δ Klste11 and Δ Klste50 mutants, which showed high sensitivity to osmotic stress, even though the other branch (SLN1) was intact. Inactivation of both branches by deletion of KlSHO1 and KlSSK2 also produced sensitivity to high salt. Interestingly, we have observed that in Δ Klste11 and Δ Klsho1 Δ Klssk2 mutants, which exhibit sensitivity to hyperosmotic stress, and contrary to what would be expected, KlHog1p becomes phosphorylated. Additionally, in mutants lacking both MAPK kinase kinases (MAPKKKs) present in K. lactis (KlSte11p and KlSsk2p), the hyperosmotic stress induced the phosphorylation and nuclear internalization of KlHog1p, but it failed to induce the transcriptional expression of KlSTL1 and the cell was unable to grow in high-osmolarity medium. KlHog1p phosphorylation via the canonical HOG pathway or in mutants where the SHO1 and SLN1 branches have been inactivated requires not only the presence of KlPbs2p but also its kinase activity. This indicates that when the SHO1 and SLN1 branches are inactivated, high-osmotic-stress conditions activate an independent input that yields active KlPbs2p, which, in turn, renders KlHog1p phosphorylation ineffective. Finally, we found that KlSte11p can alleviate the sensitivity to hyperosmotic stress displayed by a Δ Klsho1 Δ Klssk2 mutant when it is anchored to the plasma membrane by adding the KlSho1p transmembrane segments, indicating that this chimeric protein can substitute for KlSho1p and KlSsk2p.

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 Histatin 5 Initiates Osmotic Stress Response in Candida albicans via Activation of the Hog1 Mitogen-Activated Protein Kinase Pathway

2007 ◽  
Vol 6 (10) ◽  
pp. 1876-1888 ◽  
Author(s):  
Slavena Vylkova ◽  
Woong Sik Jang ◽  
Wansheng Li ◽  
Namrata Nayyar ◽  
Mira Edgerton
Keyword(s):  
Oxidative Stress ◽  
Candida Albicans ◽  
Stress Response ◽  
Protein Kinase ◽  
Osmotic Stress ◽  
Mitogen Activated Protein Kinase ◽  
Dependent Manner ◽  
Hog Pathway ◽  
Histatin 5 ◽  
Mitogen Activated Protein

ABSTRACT Histatin 5 (Hst 5) is a salivary cationic peptide that has toxicity for Candida albicans by inducing rapid cellular ion imbalance and cell volume loss. Microarray analyses of peptide-treated cells were used to evaluate global gene responses elicited by Hst 5. The major transcriptional response of C. albicans to Hst 5 was expression of genes involved in adaptation to osmotic stress, including production of glycerol (RHR2, SKO1, and PDC11) and the general stress response (CTA1 and HSP70). The oxidative-stress genes AHP1, TRX1, and GPX1 were mildly induced by Hst 5. Cell defense against Hst 5 was dependent on the Hog1 mitogen-activated protein kinase (MAPK) pathway, since C. albicans hog1/hog1 mutants were significantly hypersensitive to Hst 5 but not to Mkc1 MAPK or Cek1 MAPK mutants. Activation of the high-osmolarity glycerol (HOG) pathway was demonstrated by phosphorylation of Hog1 MAPK as well as by glycerol production following Hst 5 treatment in a dose-dependent manner. C. albicans cells prestressed with sorbitol were less sensitive to subsequent Hst 5 treatment; however, cells treated concurrently with osmotic stress and Hst 5 were hypersensitive to Hst 5. In contrast, cells subjected to oxidative stress had no difference in sensitivity to Hst 5. These results suggest a common underlying cellular response to osmotic stress and Hst 5. The HOG stress response pathway likely represents a significant and effective challenge to physiological levels of Hst 5 and other toxic peptides in fungal cells.

scholarly journals Analysis of Mitogen-Activated Protein Kinase Signaling Specificity in Response to Hyperosmotic Stress: Use of an Analog-Sensitive HOG1 Allele

2006 ◽  
Vol 5 (8) ◽  
pp. 1215-1228 ◽  
Author(s):  
Patrick J. Westfall ◽  
Jeremy Thorner
Keyword(s):  
Protein Kinase ◽  
Cross Talk ◽  
Kinase Activity ◽  
Hyperosmotic Stress ◽  
Mitogen Activated Protein Kinase ◽  
Hog Pathway ◽  
Pheromone Response ◽  
Mapk Kinase ◽  
Signaling Specificity ◽  
Mitogen Activated Protein

ABSTRACT When confronted with a marked increase in external osmolarity, budding yeast (Saccharomyces cerevisiae) cells utilize a conserved mitogen-activated protein kinase (MAPK) signaling cascade (the high-osmolarity glycerol or HOG pathway) to elicit cellular responses necessary to permit continued growth. One input that stimulates the HOG pathway requires the integral membrane protein and putative osmosensor Sho1, which recruits and enables activation of the MAPK kinase kinase Ste11. In mutants that lack the downstream MAPK kinase (pbs2Δ) or the MAPK (hog1Δ) of the HOG pathway, Ste11 activated by hyperosmotic stress is able to inappropriately stimulate the pheromone response pathway. This loss of signaling specificity is known as cross talk. To determine whether it is the Hog1 polypeptide per se or its kinase activity that is necessary to prevent cross talk, we constructed a fully functional analog-sensitive allele of HOG1 to permit acute inhibition of this enzyme without other detectable perturbations of the cell. We found that the catalytic activity of Hog1 is required continuously to prevent cross talk between the HOG pathway and both the pheromone response and invasive growth pathways. Moreover, contrary to previous reports, we found that the kinase activity of Hog1 is necessary for its stress-induced nuclear import. Finally, our results demonstrate a role for active Hog1 in maintaining signaling specificity under conditions of persistently high external osmolarity.

scholarly journals Putative Membrane Receptors Contribute to Activation and Efficient Signaling of Mitogen-Activated Protein Kinase Cascades during Adaptation of Aspergillus fumigatus to Different Stressors and Carbon Sources

mSphere ◽  
2020 ◽  
Vol 5 (5) ◽  
Author(s):  
Lilian Pereira Silva ◽  
Dean Frawley ◽  
Leandro José de Assis ◽  
Ciara Tierney ◽  
Alastair B. Fleming ◽  
...  
Keyword(s):  
Cell Wall ◽  
Protein Kinase ◽  
Aspergillus Fumigatus ◽  
Fungal Pathogen ◽  
Cell Wall Integrity ◽  
Mitogen Activated Protein Kinase ◽  
Hog Pathway ◽  
Content Type ◽  
High Osmolarity Glycerol ◽  
Mitogen Activated Protein

ABSTRACT The high-osmolarity glycerol (HOG) response pathway is a multifunctional signal transduction pathway that specifically transmits ambient osmotic signals. Saccharomyces cerevisiae Hog1p has two upstream signaling branches, the sensor histidine kinase Sln1p and the receptor Sho1p. The Sho1p branch includes two other proteins, the Msb2p mucin and Opy2p. Aspergillus fumigatus is the leading cause of pulmonary fungal diseases. Here, we investigated the roles played by A. fumigatus SlnASln1p, ShoASho1p, MsbAMsb2p, and OpyAOpy2p putative homologues during the activation of the mitogen-activated protein kinase (MAPK) HOG pathway. The shoA, msbA, and opyA singly and doubly null mutants are important for the cell wall integrity (CWI) pathway, oxidative stress, and virulence as assessed by a Galleria mellonella model. Genetic interactions of ShoA, MsbA, and OpyA are also important for proper activation of the SakAHog1p and MpkASlt2 cascade and the response to osmotic and cell wall stresses. Comparative label-free quantitative proteomics analysis of the singly null mutants with the wild-type strain upon caspofungin exposure indicates that the absence of ShoA, MsbA, and OpyA affects the osmotic stress response, carbohydrate metabolism, and protein degradation. The putative receptor mutants showed altered trehalose and glycogen accumulation, suggesting a role for ShoA, MsbA, and OpyA in sugar storage. Protein kinase A activity was also decreased in these mutants. We also observed genetic interactions between SlnA, ShoA, MsbA, and OpyA, suggesting that both branches are important for activation of the HOG/CWI pathways. Our results help in the understanding of the activation and modulation of the HOG and CWI pathways in this important fungal pathogen. IMPORTANCE Aspergillus fumigatus is an important human-pathogenic fungal species that is responsible for a high incidence of infections in immunocompromised individuals. A. fumigatus high-osmolarity glycerol (HOG) and cell wall integrity pathways are important for the adaptation to different forms of environmental adversity such as osmotic and oxidative stresses, nutrient limitations, high temperatures, and other chemical and mechanical stresses that may be produced by the host immune system and antifungal drugs. Little is known about how these pathways are activated in this fungal pathogen. Here, we characterize four A. fumigatus putative homologues that are important for the activation of the yeast HOG pathway. A. fumigatus SlnASln1p, ShoASho1p, MsbAMsb2p, and OpyAOpy2p are genetically interacting and are essential for the activation of the HOG and cell wall integrity pathways. Our results contribute to the understanding of A. fumigatus adaptation to the host environment.

scholarly journals Hog1 Mitogen-Activated Protein Kinase Plays Conserved and Distinct Roles in the Osmotolerant Yeast Torulaspora delbrueckii

2006 ◽  
Vol 5 (8) ◽  
pp. 1410-1419 ◽  
Author(s):  
María José Hernandez-Lopez ◽  
Francisca Randez-Gil ◽  
José Antonio Prieto
Keyword(s):  
Protein Kinase ◽  
Osmotic Stress ◽  
Molecular Mechanisms ◽  
Mitogen Activated Protein Kinase ◽  
Minor Role ◽  
Hog Pathway ◽  
Protection Mechanism ◽  
Torulaspora Delbrueckii ◽  
Mitogen Activated Protein ◽  
A Minor

ABSTRACT Torulaspora delbrueckii has emerged during evolution as one of the most osmotolerant yeasts. However, the molecular mechanisms underlying this unusual stress resistance are poorly understood. In this study, we have characterized the functional role of the high-osmolarity glycerol (HOG) mitogen-activated protein kinase pathway in mediating the osmotic stress response, among others, in T. delbrueckii. We show that the T. delbrueckii Hog1p homologue TdHog1p is phosphorylated after cell transfer to NaCl- or sorbitol-containing medium. However, TdHog1p plays a minor role in tolerance to conditions of moderate osmotic stress, a trait related mainly with the osmotic balance. In consonance with this, the absence of TdHog1p produced only a weak defect in the timing of the osmostress-induced glycerol and GPD1 mRNA overaccumulation. Tdhog1Δ mutants also failed to display aberrant morphology changes in response to osmotic stress. Furthermore, our data indicate that the T. delbrueckii HOG pathway has evolved to respond to specific environmental conditions and to play a pivotal role in the stress cross-protection mechanism.

scholarly journals Ptc1, a Type 2C Ser/Thr Phosphatase, Inactivates the HOG Pathway by Dephosphorylating the Mitogen-Activated Protein Kinase Hog1

2001 ◽  
Vol 21 (1) ◽  
pp. 51-60 ◽  
Author(s):  
Janel Warmka ◽  
Jennifer Hanneman ◽  
Ji Lee ◽  
Dipesh Amin ◽  
Irene Ota
Keyword(s):  
Protein Kinase ◽  
Osmotic Stress ◽  
Metal Ion ◽  
Mapk Pathway ◽  
Negative Regulator ◽  
Mitogen Activated Protein Kinase ◽  
Hog Pathway ◽  
Mitogen Activated Protein

ABSTRACT The HOG (high-osmolarity glycerol) mitogen-activated protein kinase (MAPK) pathway regulates the osmotic stress response in the yeast Saccharomyces cerevisiae. Three type 2C Ser/Thr phosphatases (PTCs), Ptc1, Ptc2, and Ptc3, have been isolated as negative regulators of this pathway. Previously, multicopy expression of PTC1 and PTC3 was shown to suppress lethality of the sln1Δ strain due to hyperactivation of the HOG pathway. In this work, we show thatPTC2 also suppresses sln1Δ lethality. Furthermore, the phosphatase activity of these PTCs was needed for suppression, as mutation of a conserved Asp residue, likely to coordinate a metal ion, inactivated PTCs. Further analysis of Ptc1 function in vivo showed that it inactivates the MAPK, Hog1, but not the MEK, Pbs2. In the wild type, Hog1 kinase activity increased transiently, ∼12-fold in response to osmotic stress, while overexpression of PTC1 limited activation to ∼3-fold. In contrast, overexpression of PTC1 did not inhibit phosphorylation of Hog1 Tyr in the phosphorylation lip, suggesting that Ptc1 does not act on Pbs2. Deletion of PTC1 also strongly affected Hog1, leading to high basal Hog1 activity and sustained Hog1 activity in response to osmotic stress, the latter being consistent with a role for Ptc1 in adaptation. In vitro, Ptc1 but not the metal binding site mutant, Ptc1D58N, inactivated Hog1 by dephosphorylating the phosphothreonine but not the phosphotyrosine residue in the phosphorylation lip. Consistent with its role as a negative regulator of Hog1, which accumulates in the nucleus upon activation, Ptc1 was found in both the nucleus and the cytoplasm. Thus, one function of Ptc1 is to inactivate Hog1.

scholarly journals Phosphothreonine Lyase Promotes p65 Degradation in a Mitogen-Activated Protein Kinase/Mitogen- and Stress-Activated Protein Kinase 1-Dependent Manner

2018 ◽  
Vol 87 (1) ◽  
Author(s):  
Mingyu Hou ◽  
Wenhui Wang ◽  
Feizi Hu ◽  
Yuanxing Zhang ◽  
Dahai Yang ◽  
...  
Keyword(s):  
Protein Kinase ◽  
Pathogenic Bacteria ◽  
Critical Role ◽  
Nuclear Factor Κb ◽  
Mapk Signaling ◽  
Mitogen Activated Protein Kinase ◽  
Dependent Manner ◽  
Content Type ◽  
Catalytic Active Site ◽  
Mitogen Activated Protein

ABSTRACT Bacterial phosphothreonine lyases have been identified to be type III secretion system (T3SS) effectors that irreversibly dephosphorylate host mitogen-activated protein kinase (MAPK) signaling to promote infection. However, the effects of phosphothreonine lyase on nuclear factor κB (NF-κB) signaling remain largely unknown. In this study, we detected significant phosphothreonine lyase-dependent p65 degradation during Edwardsiella piscicida infection in macrophages, and this degradative effect was blocked by the protease inhibitor MG132. Further analysis revealed that phosphothreonine lyase promotes the dephosphorylation and ubiquitination of p65 by inhibiting the phosphorylation of mitogen- and stress-activated protein kinase-1 (MSK1) and by inhibiting the phosphorylation of extracellular signal-related kinase 1/2 (ERK1/2), p38α, and c-Jun N-terminal kinase (JNK). Moreover, we revealed that the catalytic active site of phosphothreonine lyase plays a critical role in regulating the MAPK-MSK1-p65 signaling axis. Collectively, the mechanism described here expands our understanding of the pathogenic effector in not only regulating MAPK signaling but also regulating p65. These findings uncover a new mechanism by which pathogenic bacteria overcome host innate immunity to promote pathogenesis.

scholarly journals Induction of Interleukin 10 byBorrelia burgdorferiIs Regulated by the Action of CD14-Dependent p38 Mitogen-Activated Protein Kinase and cAMP-Mediated Chromatin Remodeling

2018 ◽  
Vol 86 (4) ◽  
Author(s):  
Bikash Sahay ◽  
Kathleen Bashant ◽  
Nicole L. J. Nelson ◽  
Rebeca L. Patsey ◽  
Shiva Kumar Gadila ◽  
...  
Keyword(s):  
Protein Kinase ◽  
Lyme Borreliosis ◽  
Human Peripheral Blood ◽  
Interleukin 10 ◽  
Mapk Signaling ◽  
Lyme Arthritis ◽  
Mitogen Activated Protein Kinase ◽  
Content Type ◽  
C3h Mice ◽  
Mitogen Activated Protein

ABSTRACTHost genotype influences the severity of murine Lyme borreliosis, caused by the spirochetal bacteriumBorrelia burgdorferi. C57BL/6 (B6) mice develop mild Lyme arthritis, whereas C3H/HeN (C3H) mice develop severe Lyme arthritis. Differential expression of interleukin 10 (IL-10) has long been associated with mouse strain differences in Lyme pathogenesis; however, the underlying mechanism(s) of this genotype-specific IL-10 regulation remained elusive. Herein we reveal a cAMP-mediated mechanism of IL-10 regulation in B6 macrophages that is substantially diminished in C3H macrophages. Under cAMP and CD14-p38 mitogen-activated protein kinase (MAPK) signaling, B6 macrophages stimulated withB. burgdorferiproduce increased amounts of IL-10 and decreased levels of arthritogenic cytokines, including tumor necrosis factor (TNF). cAMP relaxes chromatin, while p38 increases binding of the transcription factors signal transducer and activator of transcription 3 (STAT3) and specific protein 1 (SP1) to the IL-10 promoter, leading to increased IL-10 production in B6 bone marrow-derived monocytes (BMDMs). Conversely, macrophages derived from arthritis-susceptible C3H mice possess significantly less endogenous cAMP, produce less IL-10, and thus are ill equipped to mitigate the damaging consequences ofB. burgdorferi-induced TNF. Intriguingly, an altered balance between anti-inflammatory and proinflammatory cytokines and CD14-dependent regulatory mechanisms also is operative in primary human peripheral blood-derived monocytes, providing potential insight into the clinical spectrum of human Lyme disease. In line with this notion, we have demonstrated that cAMP-enhancing drugs increase IL-10 production in myeloid cells, thus curtailing inflammation associated with murine Lyme borreliosis. Discovery of novel treatments or repurposing of FDA-approved cAMP-modulating medications may be a promising avenue for treatment of patients with adverse clinical outcomes, including certain post-Lyme complications, in whom dysregulated immune responses may play a role.

scholarly journals A Redox-Sensitive Thiol in Wis1 Modulates the Fission Yeast Mitogen-Activated Protein Kinase Response to H2O2 and Is the Target of a Small Molecule

2020 ◽  
Vol 40 (7) ◽  
Author(s):  
Johanna J. Sjölander ◽  
Agata Tarczykowska ◽  
Cecilia Picazo ◽  
Itziar Cossio ◽  
Itedale Namro Redwan ◽  
...  
Keyword(s):  
Protein Kinase ◽  
Fission Yeast ◽  
Inhibitory Effect ◽  
Mitogen Activated Protein Kinase ◽  
Activation Loop ◽  
Content Type ◽  
Kinase Activation ◽  
Mitogen Activated Protein

ABSTRACT Oxidation of a highly conserved cysteine (Cys) residue located in the kinase activation loop of mitogen-activated protein kinase kinases (MAPKK) inactivates mammalian MKK6. This residue is conserved in the fission yeast Schizosaccharomyces pombe MAPKK Wis1, which belongs to the H2O2-responsive MAPK Sty1 pathway. Here, we show that H2O2 reversibly inactivates Wis1 through this residue (C458) in vitro. We found that C458 is oxidized in vivo and that serine replacement of this residue significantly enhances Wis1 activation upon addition of H2O2. The allosteric MAPKK inhibitor INR119, which binds in a pocket next to the activation loop and C458, prevented the inhibition of Wis1 by H2O2 in vitro and significantly increased Wis1 activation by low levels of H2O2 in vivo. We propose that oxidation of C458 inhibits Wis1 and that INR119 cancels out this inhibitory effect by binding close to this residue. Kinase inhibition through the oxidation of a conserved Cys residue in MKK6 (C196) is thus conserved in the S. pombe MAPKK Wis1.

scholarly journals Thiol-based direct threat sensing by the stress-activated protein kinase Hog1

2019 ◽  
Vol 12 (609) ◽  
pp. eaaw4956
Author(s):  
Angel Guerra-Moreno ◽  
Miguel A. Prado ◽  
Jessie Ang ◽  
Helena M. Schnell ◽  
Yagmur Micoogullari ◽  
...  
Keyword(s):  
Protein Kinase ◽  
Osmotic Stress ◽  
Nuclear Localization ◽  
Mitogen Activated Protein Kinase ◽  
Physical Interaction ◽  
Adaptive Responses ◽  
Mitogen Activated Protein ◽  
Arsenic Detoxification ◽  
Mechanistic Basis

The yeast stress-activated protein kinase Hog1 is best known for its role in mediating the response to osmotic stress, but it is also activated by various mechanistically distinct environmental stressors, including heat shock, endoplasmic reticulum stress, and arsenic. In the osmotic stress response, the signal is sensed upstream and relayed to Hog1 through a kinase cascade. Here, we identified a mode of Hog1 function whereby Hog1 senses arsenic through a direct physical interaction that requires three conserved cysteine residues located adjacent to the catalytic loop. These residues were essential for Hog1-mediated protection against arsenic, were dispensable for the response to osmotic stress, and promoted the nuclear localization of Hog1 upon exposure of cells to arsenic. Hog1 promoted arsenic detoxification by stimulating phosphorylation of the transcription factor Yap8, promoting Yap8 nuclear localization, and stimulating the transcription of the only known Yap8 targets, ARR2 and ARR3, both of which encode proteins that promote arsenic efflux. The related human kinases ERK1 and ERK2 also bound to arsenic in vitro, suggesting that this may be a conserved feature of some members of the mitogen-activated protein kinase (MAPK) family. These data provide a mechanistic basis for understanding how stress-activated kinases can sense distinct threats and perform highly specific adaptive responses.

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