scholarly journals Phosphorylation dynamics in a flg22 induced, heterotrimeric G protein dependent signaling network in Arabidopsis thaliana reveals a candidate PP2A phosphatase involved in AtRGS1 trafficking

2021 ◽  
Author(s):  
Justin Michael Watkins ◽  
Alan M. Jones ◽  
Justin Walley ◽  
Natalie M Clark ◽  
Daisuke Urano ◽  
...  
Keyword(s):  
Arabidopsis Thaliana ◽  
G Protein ◽  
Protein Complex ◽  
Protein A ◽  
Mitogen Activated Protein Kinase ◽  
Central Component ◽  
Dependent Manner ◽  
Heterotrimeric G Protein ◽  
Protein Interactome ◽  
Mitogen Activated Protein

flg22 is a 22 amino peptide released from bacterial flagellin a Microbe Associated Molecular 51 Pattern ( that is recognized by the plant cell as a signal indicating that bacteria are present. On its own, flg22 initiates a rapid increase in cytoplasmic calcium, extracellular reactive oxygen species, and activation of a Mitogen Activated Protein Kinase (cascade all of which are activated within 15 minutes after the cell perceives flg22. Here we show a massive change in protein abundance and phosphorylation state of the Arabidopsis root cell proteome within this 15 minute duration in wildtype and a mutant deficient in G protein coupled signaling Integration of phosphoproteome with protein protein interactome data followed by network topology analyses discovered that many of the flg22 induced phosphoproteome changes fall on proteins that comprise the G protein interactome and on the most highly populated hubs of the immunity network approximately 95% of the phosphorylation changes in the G protein interactome depend on a functional heterotrimeric G protein complex some occur on proteins that interact directly with components of G coupled signal transduction. One of these is ATBα, a substrate recognition sub-unit of the PP2A Ser/Thr phosphatase and an interactor to Arabidopsis thaliana REGULATOR OF G SIGNALING 1 protein (a 7 transmembrane spanning modulator of the nucleotide binding state of the core G protein complex. AtRGS1 is phosphorylated by BAK1, a component of the flg22 receptor, to initiate AtRGS1 endocytosis. A null mutation of ATB α confer s high 67 basal endocytosis of AtRGS1 suggesting sustained phosphorylated status. Loss of ATB α confers 68 trait s associated with loss of AtRGS1. Because the basal level of AtRGS1 is lower in the atbα null mutant in a proteasome dependent manner we propose that phosphorylation dependent endocytosis of AtRGS1 is part of a mechanism to degrade AtRGS1 which then sustains activation of the 71 G protein complex Thus, the role of ATB α is now established as a central component of phosphorylation dependent regulation of system dynamics in innate immunity

scholarly journals A Sphingolipid Elicitor-Inducible Mitogen-Activated Protein Kinase Is Regulated by the Small GTPase OsRac1 and Heterotrimeric G-Protein in Rice

2005 ◽  
Vol 138 (3) ◽  
pp. 1644-1652 ◽  
Author(s):  
Damien Lieberherr ◽  
Nguyen Phuong Thao ◽  
Ayako Nakashima ◽  
Kenji Umemura ◽  
Tsutomu Kawasaki ◽  
...  
Keyword(s):  
Protein Kinase ◽  
G Protein ◽  
Small Gtpase ◽  
Mitogen Activated Protein Kinase ◽  
Heterotrimeric G Protein ◽  
Mitogen Activated Protein

scholarly journals Leptin activates the promoter of the interleukin-1 receptor antagonist through p42/44 mitogen-activated protein kinase and a composite nuclear factor kappaB/PU.1 binding site

2003 ◽  
Vol 370 (2) ◽  
pp. 591-599 ◽  
Author(s):  
Magali G. DREYER ◽  
Cristiana E. JUGE-AUBRY ◽  
Cem GABAY ◽  
Ursula LANG ◽  
Françoise ROHNER-JEANRENAUD ◽  
...  
Keyword(s):  
Receptor Antagonist ◽  
Protein Complex ◽  
Leptin Receptor ◽  
Interleukin 1 ◽  
Mitogen Activated Protein Kinase ◽  
Dependent Manner ◽  
Nuclear Factor ◽  
Composite Element ◽  
Interleukin 1 Receptor Antagonist ◽  
Mitogen Activated Protein

We have recently shown that leptin strongly induces the expression and secretion of the interleukin-1 receptor antagonist (IL-1Ra) [Gabay, Dreyer, Pellegrinelli, Chicheportiche and Meier (2001) J. Clin. Endocrinol. Metab. 86, 783—791] in monocytes. However, the intracellular signalling mechanisms involved remained unknown. We now demonstrate that the activation of the IL-1Ra promoter by leptin is strictly dependent on the presence of the long form of the leptin receptor (OB-Rb), and that it also requires the activation of the p42/44 mitogen-activated protein kinases (MAPKs) as well as the presence of a nuclear factor κB (NF-κB)/PU.1 composite site at position −80 of the IL-1Ra promoter. Although leptin is capable of activating a NF-κB reporter element in transient transfection experiments, the protein complex binding to the NF-κB/PU.1 site of the IL-1Ra promoter is not composed of the p65/p50 subunits of NF-κB, as is evident in electrophoretic gel mobility-shift experiments. In contrast, a protein complex which does not contain PU.1 binds to this composite element in a leptin-dependent manner. In summary, we characterize the signalling pathway for leptin and OB-Rb involved in the induction of IL-1Ra, involving p42/44 MAPK, and a yet uncharacterized complex of transcription factor(s) binding to a NF-κB/PU.1 composite element of the IL-1Ra promoter.

scholarly journals Mitogen-Activated Protein Kinase Phosphatase 1 (MKP1) Negatively Regulates the Production of Reactive Oxygen Species During Arabidopsis Immune Responses

2019 ◽  
Vol 32 (4) ◽  
pp. 464-478 ◽  
Author(s):  
Viviana Escudero ◽  
Miguel Ángel Torres ◽  
Magdalena Delgado ◽  
Sara Sopeña-Torres ◽  
Sanjay Swami ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Protein Kinase ◽  
Immune Responses ◽  
G Protein ◽  
Reactive Oxygen ◽  
Mitogen Activated Protein Kinase ◽  
Oxygen Species ◽  
Heterotrimeric G Protein ◽  
Genetic Ablation ◽  
Mitogen Activated Protein

Genetic ablation of the β subunit of the heterotrimeric G protein complex in agb1-2 confers defective activation of microbe-associated molecular pattern (MAMP)-triggered immunity, resulting in agb1-2 enhanced susceptibility to pathogens like the fungus Plectosphaerella cucumerina BMM. A mutant screen for suppressors of agb1-2 susceptibility (sgb) to P. cucumerina BMM identified sgb10, a new null allele (mkp1-2) of the mitogen-activated protein kinase phosphatase 1 (MKP1). The enhanced susceptibility of agb1-2 to the bacterium Pseudomonas syringae pv. tomato DC3000 and the oomycete Hyaloperonospora arabidopsidis is also abrogated by mkp1-2. MKP1 negatively balances production of reactive oxygen species (ROS) triggered by MAMPs, since ROS levels are enhanced in mkp1. The expression of RBOHD, encoding a NADPH oxidase–producing ROS, is upregulated in mkp1 upon MAMP treatment or pathogen infection. Moreover, MKP1 negatively regulates RBOHD activity, because ROS levels upon MAMP treatment are increased in mkp1 plants constitutively overexpressing RBOHD (35S::RBOHD mkp1). A significant reprograming of mkp1 metabolic profile occurs with more than 170 metabolites, including antimicrobial compounds, showing differential accumulation in comparison with wild-type plants. These results suggest that MKP1 functions downstream of the heterotrimeric G protein during MAMP-triggered immunity, directly regulating the activity of RBOHD and ROS production as well as other immune responses.

scholarly journals Phosphorylation dynamics in a flg22-induced, G-protein dependent network in Arabidopsis thaliana

2021 ◽  
Author(s):  
Justin M Watkins ◽  
Natalie M Clark ◽  
Gaoyuan Song ◽  
Celio Cabral Oliveira ◽  
Bharat Mishra ◽  
...  
Keyword(s):  
G Protein ◽  
Protein Complex ◽  
Protein Abundance ◽  
Dependent Manner ◽  
Arabidopsis Root ◽  
Protein Interactome ◽  
Massive Change ◽  
Induced Changes ◽  
Cell Proteome ◽  
G Protein Coupled

flg22 is recognized by the plant cell as a signal indicating that bacteria are present. Here we show a rapid and massive change in protein abundance and phosphorylation state of the Arabidopsis root cell proteome in wildtype and a mutant deficient in G-protein coupled signaling. Many of the flg22-induced changes fall on proteins comprising the G protein interactome and on highly populated hubs of the immunity network. Approximately 95% of the phosphorylation changes in the G-protein interactome depend on a functional G protein complex; some on proteins in the G protein interactome. One of these is ATB?, an interactor to REGULATOR OF G SIGNALING 1 protein (AtRGS1), a 7-transmembrane spanning modulator of the nucleotide-binding state of the core G protein complex. A null mutation of ATB? confers basal endocytosis of AtRGS1. AtRGS1 level is lower in the atb? mutant in a proteasome-dependent manner. We propose that phosphorylation-dependent endocytosis of AtRGS1 is part of the mechanism to degrade AtRGS1 thus sustaining activation of the G protein complex required for regulation of system dynamics in innate immunity.

Aluminum potentiates P(i) transport stimulation induced by fluoride in osteoblast-like cells

1996 ◽  
Vol 271 (4) ◽  
pp. E694-E701
Author(s):  
T. Imai ◽  
D. Burgener ◽  
X. Zhen ◽  
J. P. Benjour ◽  
J. Caverzasio
Keyword(s):  
Protein Kinase ◽  
Tyrosine Phosphorylation ◽  
G Protein ◽  
Calf Serum ◽  
Mitogen Activated Protein Kinase ◽  
Dependent Manner ◽  
Deferoxamine Mesylate ◽  
Mitogen Activated Protein ◽  
Umr 106 ◽  
G Protein Coupled

The effect of aluminum (AI) on inorganic phosphate (P(i)) transport stimulation induced by fluoride (F) was investigated in MC3T3-E1 osteoblast-like cells. Al potentiated the increase in P(i) transport activity induced by F in a dose- and time-dependent manner. Results obtained with deferoxamine mesylate, an Al chelator, suggest that a fluoroalumino complex is probably the active F molecule responsible for the change in P(i) transport observed in this study. The signaling pathway responsible for the stimulation of P(i) transport by F+Al likely involves a tyrosine phosphorylation process but neither a protein kinase C nor a mitogen-activated protein kinase pathway. As previously found in UMR-106 cells for F alone, F+Al potentiated the change in P(i) transport induced by fetal calf serum. A similar interaction was found between F+Al and thrombin acting through a G protein-coupled receptor. These observations are compatible with the hypothesis that F+Al could interact with G protein-coupled receptors associated with a signaling tyrosine phosphorylation process involved in the regulation of P(i), transport in osteoblast-like cells.

Mitochondrial ROS initiate phosphorylation of p38 MAP kinase during hypoxia in cardiomyocytes

2002 ◽  
Vol 282 (6) ◽  
pp. L1324-L1329 ◽  
Author(s):  
Andre Kulisz ◽  
Ningfang Chen ◽  
Navdeep S. Chandel ◽  
Zuohui Shao ◽  
Paul T. Schumacker
Keyword(s):  
Kinase Inhibitor ◽  
Anion Channel ◽  
P38 Map Kinase ◽  
Proximal Region ◽  
Mitogen Activated Protein Kinase ◽  
Ros Generation ◽  
Dependent Manner ◽  
Adaptive Responses ◽  
Mitochondrial Ros ◽  
Mitogen Activated Protein

The p38 mitogen-activated protein kinase (MAPK) is phosphorylated in response to oxidative stress. Mitochondria in cardiomyocytes increase their generation of reactive oxygen species (ROS) during hypoxia (1–5% O2). These ROS participate in signal transduction pathways involved in adaptive responses, including ischemic preconditioning and gene transcription. The present study therefore tested the hypothesis that hypoxia induces p38 MAPK phosphorylation by augmenting mitochondrial ROS generation. In cardiomyocytes, phosphorylation of p38 was observed in a Po 2-dependent manner during hypoxia. This response was inhibited by rotenone, thenoyltrifluoroacetone, and myxothiazol, inhibitors of mitochondrial complexes I, II, and III, respectively. A similar inhibition was observed in the cells pretreated with anion channel inhibitor DIDS, which may block ROS release from mitochondria. During normoxia, increases in mitochondrial ROS elicited by azide (1–2 mM) or by the mitochondrial inhibitor antimycin A caused increased phosphorylation of p38. Brief treatment with exogenous H2O2 during normoxia also induced phosphorylation of p38 as hypoxia, but this effect was not abolished by myxothiazol or DIDS. The antioxidant N-acetyl-cysteine abolished the p38 response to hypoxia, presumably by scavenging H2O2, but the mitogen extracellular receptor kinase inhibitor PD-98059 did not inhibit p38 phosphorylation during hypoxia. Thus physiological hypoxia leads to p38 phosphorylation through a mechanism that requires electron flux in the proximal region of the mitochondrial electron transport chain, which suggests that either H2O2 or superoxide participates in activating that process.

scholarly journals G-Protein β Subunit of Cochliobolus heterostrophus Involved in Virulence, Asexual and Sexual Reproductive Ability, and Morphogenesis

2004 ◽  
Vol 3 (6) ◽  
pp. 1653-1663 ◽  
Author(s):  
Sherif Ganem ◽  
Shun-Wen Lu ◽  
Bee-Na Lee ◽  
David Yu-Te Chou ◽  
Ruthi Hadar ◽  
...  
Keyword(s):  
Map Kinase ◽  
G Protein ◽  
Signal Transduction Pathway ◽  
Cochliobolus Heterostrophus ◽  
Wild Type ◽  
Heterotrimeric G Protein ◽  
Reproductive Ability ◽  
Pathway Gene ◽  
Mitogen Activated Protein ◽  
Nuclear Degradation

ABSTRACT Previous work established that mutations in mitogen-activated protein (MAP) kinase (CHK1) and heterotrimeric G-protein α (Gα) subunit (CGA1) genes affect the development of several stages of the life cycle of the maize pathogen Cochliobolus heterostrophus. The effects of mutating a third signal transduction pathway gene, CGB1, encoding the Gβ subunit, are reported here. CGB1 is the sole Gβ subunit-encoding gene in the genome of this organism. cgb1 mutants are nearly wild type in vegetative growth rate; however, Cgb1 is required for appressorium formation, female fertility, conidiation, regulation of hyphal pigmentation, and wild-type virulence on maize. Young hyphae of cgb1 mutants grow in a straight path, in contrast to those of the wild type, which grow in a wavy pattern. Some of the phenotypes conferred by mutations in CGA1 are found in cgb1 mutants, suggesting that Cgb1 functions in a heterotrimeric G protein; however, there are also differences. In contrast to the deletion of CGA1, the loss of CGB1 is not lethal for ascospores, evidence that there is a Gβ subunit-independent signaling role for Cga1 in mating. Furthermore, not all of the phenotypes conferred by mutations in the MAP kinase CHK1 gene are found in cgb1 mutants, implying that the Gβ heterodimer is not the only conduit for signals to the MAP kinase CHK1 module. The additional phenotypes of cgb1 mutants, including severe loss of virulence on maize and of the ability to produce conidia, are consistent with CGB1 being unique in the genome. Fluorescent DNA staining showed that there is often nuclear degradation in mature hyphae of cgb1 mutants, while comparable wild-type cells have intact nuclei. These data may be genetic evidence for a novel cell death-related function of the Gβ subunit in filamentous fungi.

scholarly journals Platyphyllenone Induces Autophagy and Apoptosis by Modulating the AKT and JNK Mitogen-Activated Protein Kinase Pathways in Oral Cancer Cells

2021 ◽  
Vol 22 (8) ◽  
pp. 4211
Author(s):  
Yen-Tze Liu ◽  
Hsin-Yu Ho ◽  
Chia-Chieh Lin ◽  
Yi-Ching Chuang ◽  
Yu-Sheng Lo ◽  
...  
Keyword(s):  
Protein Kinase ◽  
Oral Cancer ◽  
Protein Expression ◽  
Caspase 3 ◽  
Therapeutic Option ◽  
Mapk Signaling ◽  
Mitogen Activated Protein Kinase ◽  
Dependent Manner ◽  
Cancer Proliferation ◽  
Mitogen Activated Protein

Platyphyllenone is a type of diarylheptanoid that exhibits anti-inflammatory and chemoprotective effects. However, its effect on oral cancer remains unclear. In this study, we investigated whether platyphyllenone can promote apoptosis and autophagy in SCC-9 and SCC-47 cells. We found that it dose-dependently promoted the cleavage of PARP; caspase-3, -8, and -9 protein expression; and also led to cell cycle arrest at the G2/M phase. Platyphyllenone up-regulated LC3-II and p62 protein expression in both SCC-9 and SCC-47 cell lines, implying that it can induce autophagy. Furthermore, the results demonstrated that platyphyllenone significantly decreased p-AKT and increased p-JNK1/2 mitogen-activated protein kinase (MAPK) signaling pathway in a dose-dependent manner. The specific inhibitors of p-JNK1/2 also reduced platyphyllenone-induced cleavage of PARP, caspase-3, and caspase -8, LC3-II and p62 protein expression. These findings are the first to demonstrate that platyphyllenone can induce both autophagy and apoptosis in oral cancers, and it is expected to provide a therapeutic option as a chemopreventive agent against oral cancer proliferation.

Docosahexaenoic Acid, a Peroxisome Proliferator-Activated Receptor-α Activator, Induces Apoptosis in Vascular Smooth Muscle Cells by Activation of P38 Mitogen-Activated Protein Kinase

Hypertension ◽  
2000 ◽  
Vol 36 (suppl_1) ◽  
pp. 679-679
Author(s):  
Quy N Diep ◽  
Rhian M Touyz ◽  
Ernesto L Schiffrin
Keyword(s):  
Smooth Muscle ◽  
Cytochrome C ◽  
Docosahexaenoic Acid ◽  
Vascular Smooth Muscle ◽  
Morphological Changes ◽  
Mitogen Activated Protein Kinase ◽  
Peroxisome Proliferator ◽  
Dependent Manner ◽  
Mitogen Activated Protein ◽  
P38 Mapks

9 Omega-3 fatty acids (n-3 FAs) exert a blood pressure-lowering effect in hypertension, possibly by influencing vascular structure. We previously demonstrated that n-3 FAs might induce vascular smooth muscle cell (VSMC) apoptosis, which could exert an effect on structure of blood vessels. This study investigated signaling pathways through which n-3 FAs mediate apoptosis in VSMCs. Cultured Mesenteric VSMCs from Sprague Dawley rats were stimulated with docosahexaenoic acid (DHA), a representative n-3 FA. Morphological changes of apoptosis and DNA fragmentation were examined by phase-contrast microscopy and fluorescence microscopy with Hoechst 33342 staining. To clarify possible pathways of apoptosis, expression of phosphorylated p38 mitogen-activated protein kinases (p38 MAPKs), bax, bcl-2, cytochrome C and peroxisome proliferator-activated receptors-α (PPARs-α) was evaluated by Western blot analysis. DHA treatment induced cell shrinkage, cell membrane blebbing and apoptotic bodies in VSMCs. DHA increased apoptosis (%) in a time-dependent manner to 1.5±0.1, 3.6±0.5, 7.1±0.4, 22.5±0.6, 50.8±1.8 and 61.4±0.9 after 0, 1, 3, 6, 17, and 24 h, respectively. DHA time-dependently activated p38 MAPKs, bax, PPARs-α and cytochrome C with maximal effects obtained after 5, 30 min, 1 h and 3 h, respectively to 551±42, 245±55, 310±12 and 407±14.7 % of controls, respectively. SB-203580 (10 -5 M) and SB-202190 (10 -5 M), selective p38 inhibitors, reduced DHA-elicited apoptosis and expression of PPARs-α, but had no effect on expression of bax or cytochrome C. The present results indicate that DHA induces apoptosis in VSMCs through at least two distinct mechanisms: (i) a p38-dependent pathway that regulates PPAR-α and (ii) a p38-independent pathway via dissipation of mitochondrial transmembrane potential. The death-signaling pathway mediated by DHA may involve an integration of these multiple pathways. By triggering VSMC apoptosis, DHA could play a pathophysiological role in vascular remodeling in cardiovascular disease.

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