Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P51812 (mitogen-activated protein)
 10,636 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Chorispora bungeana Fisch. and C.A. Mey (Chorispora bungeana) is a rare alpine subnival plant species that is highly capable of resisting freezing environment. Since it is a stress-tolerant plant, we investigated the participation of mitogen-activated protein kinases (MAPKs) as possible mediators of abiotic stresses. We have isolated from Chorispora bungeana a new MAPK cDNA CbMAPK3 which encodes a 369 amino-acid protein with moderate to high nucleotide sequence similarity to previously reported plant MAPK genes. CbMAPK3 contains all 11 of the MAPK conserved subdomains and the phosphorylation motif TEY. The transcripts of CbMAPK3 were detected and no tissue-specific expression were observed in both roots and leaves, The transcripts of CbMAPK3 accumulated highly and rapidly when Chorispora bungeana treated with cold (4 and -4 degrees C), ABA and salinity stress. These results indicate that the CbMAPK3 may play an important role in response to environmental stresses.
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PMID:Molecular cloning and characterization of a novel MAP kinase gene in Chorispora bungeana. 1653 Oct 60

Protein phosphorylation is the most important mechanism for controlling many fundamental cellular processes in all living organisms including plants. A specific class of serine/threonine protein kinases, the mitogen-activated protein kinases (MAP kinases) play a central role in the transduction of various extra- and intracellular signals and are conserved throughout eukaryotes. These generally function via a cascade of networks, where MAP kinase (MAPK) is phosphorylated and activated by MAPK kinase (MAPKK), which itself is activated by MAPKK kinase (MAPKKK). Signaling through MAP kinase cascade can lead to cellular responses including cell division, differentiation as well as response to various stresses. In plants, MAP kinases are represented by multigene families and are organized into a complex network for efficient transmission of specific stimuli. Putative plant MAP kinase cascades have been postulated based on experimental analysis of in vitro interactions between specific MAP kinase components. These cascades have been tested in planta following expression of epitope-tagged kinases in protoplasts. It is known that signaling for cell division and stress responses in plants are mediated through MAP kinases and even auxin, ABA and possibly ethylene and cytokinin also utilize a MAP kinase pathway. Most of the biotic (pathogens and pathogen-derived elicitors) including wounding and abiotic stresses (salinity, cold, drought, and oxidative) can induce defense responses in plants through MAP kinase pathways. In this article we have covered the historical background, biochemical assay, activation/inactivation, and targets of MAP kinases with emphasis on plant MAP kinases and the responses regulated by them. The cross-talk between plant MAP kinases is also discussed to bring out the complexity within this three-component module.
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PMID:Signaling through MAP kinase networks in plants. 1680 44

Among abiotic stresses, high salinity stress is the most severe environmental stress, which impairs crop production on at least 20% of irrigated land worldwide. In response to high salinity stress, various genes get upregulated, the products of which are involved either directly or indirectly in plant protection. Some of the genes encoding osmolytes, ion channels, receptors, components of calcium signaling, and some other regulatory signaling factors or enzymes are able to confer salinity-tolerant phenotypes when transferred to sensitive plants. Overall, the susceptibility or tolerance to high salinity stress in plants is a coordinated action of multiple stress responsive genes, which also cross talk with other components of stress signal transduction pathways. High salinity exerts its negative impact mainly by disrupting the ionic and osmotic equilibrium of the cell. In saline soils, high levels of sodium ions lead to plant growth inhibition and even death; therefore, mechanisms of salinity tolerance involve sequestration of Na(+) and Cl(-) in vacuoles of the cells, blocking of Na(+) entry into the cell, Na(+) exclusion from the transpiration stream, and some other mechanisms that help in salinity tolerance. Understanding these mechanisms of stress tolerance, along with a plethora of genes involved in the stress signaling network, is important to improve high salinity stress tolerance in crops plants. This chapter first describes the adverse effect of salinity stress and general pathway for the plant stress response, followed by roles of various ion pumps, calcium, SOS pathways, ABA, transcription factors, mitogen-activated protein kinases, glycine betaine, proline, reactive oxygen species, and DEAD-box helicases in salinity stress tolerance. The cross-tolerance between stresses is also mentioned.
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PMID:Mechanisms of high salinity tolerance in plants. 1787 32

SB203580 is a specific inhibitor of p38 mitogen-activated protein (MAP) kinase and has been widely used to investigate the physiological roles of p38 in animal and yeast cells. Here by using an epidermal strip bioassay, laser-scanning confocal microscopy and whole-cell patch clamp analysis, we assess the effects of pyridinyl imidazoles-like SB203580 on the H(2)O(2) signaling in guard cells of Vicia faba L. The results indicated that SB203580 blocks H(2)O(2)- or ABA-induced stomatal closure, ABA-induced H(2)O(2) generation, and decrease in K(+) fluxing across plasma membrane of Vicia guard cells by application of ABA and H(2)O(2), whereas its analog SB202474 had no effect on these events. Thus, these results suggest that activation of p38-like MAP kinase modulates guard cell ROS signaling in response to stress.
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PMID:The involvement of a P38-like MAP kinase in ABA-induced and H2O2-mediated stomatal closure in Vicia faba L. 1792 17

We isolated an Arabidopsis ABA-insensitive mutant, ais143, by activation tagging screen. T-DNA was found to be located in the coding region of a putative mitogen-activated protein (MAP) kinase kinase kinase (MAP3K) gene, Raf10, thereby abolishing its expression in the mutant. ais143 exhibited reduced seed dormancy as well as reduced ABA sensitivity. The phenotypes were complemented by the wild-type Raf10 gene, and the overexpression (OX) of Raf10 resulted in delayed seed germination and enhanced ABA sensitivity. Raf10 has high sequence identity to another MAP3K, Raf11. Parallel analysis of Raf11 knockout (KO) and OX lines showed that their phenotypes were similar to those of Raf10 KO and OX lines. An ais143 raf11 double mutant exhibited stronger phenotypes than single mutants, indicating the functional redundancy between Raf10 and Raf11. Transcript analysis revealed that the expression of many ABA-associated genes, including the key regulatory genes ABI3 and ABI5, was altered in the Raf10 and Raf11 OX lines. Recombinant Raf10 and Raf11 proteins exhibited kinase activity, which was inhibited by the MAP3K inhibitor BAY 43-9006 but not by the MAP2K inhibitor U0126. Collectively, our data indicate that Raf10 and Raf11 kinases are important regulators of seed dormancy and ABA response and that they affect the expression of ABI3, ABI5 and other ABA-regulated genes.
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PMID:Arabidopsis putative MAP kinase kinase kinases Raf10 and Raf11 are positive regulators of seed dormancy and ABA response. 2532 4

The old observation that plants preferentially synthesize flavonoids with respect to the wide range of phenylpropanoid structures when exposed to high doses of UV-B radiation has supported the view that flavonoids are primarily involved in absorbing the shortest solar wavelengths in photoprotection. However, there is compelling evidence that the biosynthesis of flavonoids is similarly upregulated in response to high photosynthetically active radiation in the presence or in the absence of UV-radiation, as well as in response to excess metal ions and photosynthetic redox unbalance. This supports the hypothesis that flavonoids may play prominent roles as scavengers of reactive oxygen species (ROS) generated by light excess. These 'antioxidant' functions of flavonoids appears robust, as maintained between different life kingdoms, e.g., plants and animals. The ability of flavonoids to buffer stress-induced large alterations in ROS homeostasis and, hence, to modulate the ROS-signaling cascade, is at the base of well-known functions of flavonoids as developmental regulators in both plants and animals. There is both long and very recent evidence indeed that, in plants, flavonoids may strongly affect phytohormone signaling, e.g., auxin and abscisic acid signaling. This function is served by flavonoids in a very low (nM) concentration range and involves the ability of flavonoids to inhibit the activity of a wide range of protein kinases, including but not limited to mitogen-activated protein kinases, that operate downstream of ROS in the regulation of cell growth and differentiation. For example, flavonoids inhibit the transport of auxin acting on serine-threonine PINOID (PID) kinases that regulate the localization of auxin efflux facilitators PIN-formed (PIN) proteins. Flavonoids may also determine auxin gradients at cellular and tissue levels, and the consequential developmental processes, by reducing auxin catabolism. Recent observations lead to the hypothesis that regulation/modulation of auxin transport/signaling is likely an ancestral function of flavonoids. The antagonistic functions of flavonoids on ABA-induced stomatal closure also offer novel hypotheses on the functional role of flavonoids in plant-environment interactions, in early as well as in modern terrestrial plants. Here, we surmise that the regulation of phytohormone signaling might have represented a primary function served by flavonols for the conquest of land by plants and it is still of major significance for the successful acclimation of modern terrestrial plants to a severe excess of radiant energy.
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PMID:Modulation of Phytohormone Signaling: A Primary Function of Flavonoids in Plant-Environment Interactions. 3007 75

The clade A protein phosphatase 2C Highly ABA-Induced 1 (HAI1) plays an important role in stress signaling, yet little information is available on HAI1-regulated phosphoproteins. Quantitative phosphoproteomics identified phosphopeptides of increased abundance in hai1-2 in unstressed plants and in plants exposed to low-water potential (drought) stress. The identity and localization of the phosphoproteins as well as enrichment of specific phosphorylation motifs indicated that these phosphorylation sites may be regulated directly by HAI1 or by HAI1-regulated kinases including mitogen-activated protein kinases, sucrose non-fermenting-related kinase 2, or casein kinases. One of the phosphosites putatively regulated by HAI1 was S313/S314 of AT-Hook-Like10 (AHL10), a DNA-binding protein of unclear function. HAI1 could directly dephosphorylate AHL10 in vitro, and the level of HAI1 expression affected the abundance of phosphorylated AHL10 in vivo. AHL10 S314 phosphorylation was critical for restriction of plant growth under low-water potential stress and for regulation of jasmonic acid and auxin-related gene expression as well as expression of developmental regulators including Shootmeristemless These genes were also misregulated in hai1-2 AHL10 S314 phosphorylation was required for AHL10 complexes to form foci within the nucleoplasm, suggesting that S314 phosphorylation may control AHL10 association with the nuclear matrix or with other transcriptional regulators. These data identify a set of HAI1-affected phosphorylation sites, show that HAI1-regulated phosphorylation of AHL10 S314 controls AHL10 function and localization, and indicate that HAI1-AHL10 signaling coordinates growth with stress and defense responses.
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PMID:Phosphoproteomics of Arabidopsis Highly ABA-Induced1 identifies AT-Hook-Like10 phosphorylation required for stress growth regulation. 3067 Jun 55