scholarly journals BcSAK1, a Stress-Activated Mitogen-Activated Protein Kinase, Is Involved in Vegetative Differentiation and Pathogenicity in Botrytis cinerea

2006 ◽  
Vol 6 (2) ◽  
pp. 211-221 ◽  
Author(s):  
Nadja Segmüller ◽  
Ursula Ellendorf ◽  
Bettina Tudzynski ◽  
Paul Tudzynski
Keyword(s):  
Oxidative Stress ◽  
Protein Kinase ◽  
Botrytis Cinerea ◽  
Oxidative Stress Response ◽  
Mitogen Activated Protein Kinase ◽  
Stress Response Genes ◽  
Mitogen Activated Protein ◽  
Functional Features ◽  
Sclerotial Development ◽  
And Oxidative Stress

ABSTRACT The gene bcsak1, encoding a mitogen-activated protein kinase (MAPK) of Botrytis cinerea, was cloned and characterized. The protein has high homology to the yeast Hog1 and to corresponding MAPKs from filamentous fungi, but it shows unique functional features. The protein is phosphorylated under osmotic stress, specific fungicides, and oxidative stress mediated by H2O2 and menadione. Northern blot analyses indicate that only a subset of typical oxidative stress response genes is regulated by BcSAK1. In contrast to most other fungal systems, Δbcsak1 mutants are significantly impaired in vegetative and pathogenic development: they are blocked in conidia formation, show increased sclerotial development, and are unable to penetrate unwounded plant tissue. These data indicate that in B. cinerea the stress-activated MAPK cascade is involved in essential differentiation programs.

scholarly journals The Mitogen-Activated Protein Kinase BcSak1 of Botrytis cinerea Is Required for Pathogenic Development and Has Broad Regulatory Functions Beyond Stress Response

2012 ◽  
Vol 25 (6) ◽  
pp. 802-816 ◽  
Author(s):  
Jens Heller ◽  
Nadja Ruhnke ◽  
José Juan Espino ◽  
Michelli Massaroli ◽  
Isidro Gonzalez Collado ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Stress Response ◽  
Protein Kinase ◽  
Osmotic Stress ◽  
Botrytis Cinerea ◽  
Fluorescent Protein ◽  
Mitogen Activated Protein Kinase ◽  
In Planta ◽  
Mitogen Activated Protein

The mitogen-activated protein kinase (MAPK) BcSak1 of Botrytis cinerea is activated upon exposure to H2O2 and, hence, might be involved in coping with oxidative stress during infection. However, beside osmotic and oxidative stress sensitivity, Δbcsak1 mutants have a pleiotropic phenotype, as they do not produce conidia and are unable to penetrate unwounded host tissue. In this study, the role of BcSak1 was investigated in the stress response and during infection of French beans by Botrytis cinerea. Using a macroarray approach, it was shown that BcSak1 is only marginally involved in the specific oxidative stress response. In fact, the induction of several genes after oxidative stress treatment is BcSak1-dependent, but most of these genes are also induced under conditions of osmotic stress. The majority of genes regulated by BcSak1 are not involved in the stress response at all. Using a translational fusion of BcSak1 to green fluorescent protein, it was shown clearly that the localization of this MAPK depends on the type of stress being applied; it associates rapidly to the nucleus only under osmotic stress. Therefore, a model is proposed in which BcSak1 acts in the cytosol by activation of one or more transcription factors under oxidative stress and, at the same time, it reacts to osmotic stress by migrating to the nucleus. Interestingly, the MAPK is also involved in the regulation of secondary metabolism, as the major phytotoxins secreted by this fungus are reduced in the Δbcsak1 deletion mutant. Experiments done in planta underlined the essential role of BcSak1 in the early stages of infection, when it translocates to the nucleus and then changes to cytosolic distribution during hyphal growth within the tissue.

Effects of edpetiline from Fritillaria on inflammation and oxidative stress induced by LPS stimulation in RAW264.7 macrophages

2021 ◽  
Author(s):  
Hongli Zhang ◽  
Xiaoqing Xu ◽  
Zhenhua Liu ◽  
Dongxiao Sun-Waterhouse ◽  
Jinmei Wang ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Protein Kinase ◽  
Mrna Expression ◽  
Signaling Pathway ◽  
Mitogen Activated Protein Kinase ◽  
Raw264.7 Macrophages ◽  
Mitogen Activated Protein ◽  
Protein Kinase Signaling ◽  
Kinase Signaling Pathway ◽  
And Oxidative Stress

Abstract The dry bulbs of Fritillaria cirrhosa species can help resolve phlegm, soothe cough, clear heat, and moisten the lung, and the main active components responsible for these effect are its alkaloids. However, it is unclear whether or how edpetiline in Fritillaria can inhibit the excessive inflammatory response and oxidative stress. In this research, we aimed to examine this aspect using lipopolysaccharide (LPS)-stimulated RAW264.7 macrophages as an inflammatory model. The quantitative real-time polymerase chain reaction and western blot analysis results showed that edpetiline significantly inhibited the content and mRNA expression levels of proinflammatory cytokines (TNF-α and IL-6) in LPS-induced RAW264.7 cells, significantly increased the mRNA expression of IL-4 (anti-inflammatory cytokine), and markedly downregulated the inflammatory mediators inductible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) mRNA and protein expression levels. The oxidative stress induced by LPS was also inhibited by edpetiline, as the level of intracellular reactive oxygen species decreased notably. Edpetiline may exert anti-inflammatory and antioxidant effects through inhibiting the phosphorylation of IκB and the nuclear transcription of nuclear transcription factor-κB p65 and decreasing the phosphorylation of p38 and ERK in the mitogen-activated protein kinase signaling pathway, without activating the JNK/mitogen-activated protein kinase signaling pathway. These findings suggest that edpetiline may be a potential therapeutic agent for the prevention or treatment of inflammation- and oxidative stress-related pathophysiological processes and diseases.

Age-Related Changes in Activation of Mitogen-Activated Protein Kinase Cascades by Oxidative Stress

1998 ◽  
Vol 3 (1) ◽  
pp. 23-27 ◽  
Author(s):  
Kathryn Z Guyton ◽  
Myriani Gorospe ◽  
Xiantao Wang ◽  
Yolanda D Mock ◽  
Gertrude C Kokkonen ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Protein Kinase ◽  
Mitogen Activated Protein Kinase ◽  
Age Related ◽  
Mitogen Activated Protein ◽  
Age Related Changes
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