Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:2.7.12.2 (MEK)
 18,161 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Ethylene signal transduction involves ETR1, a two-component histidine protein kinase receptor. ETR1 functions upstream of the negative regulator CTR1. The similarity of CTR1 to members of the Raf family of mitogen-activated protein kinase kinase kinases (MAPKKKs) suggested that ethylene signaling in plants involves a MAPK pathway, but no direct evidence for this has been provided. Here we show that distinct MAPKs are activated by the ethylene precursor aminocyclopropane-1-carboxylic acid (ACC) in Medicago and Arabidopsis: In Medicago, the ACC-activated MAPKs were SIMK and MMK3, while in Arabidopsis MPK6 and another MAPK were identified. Medicago SIMKK specifically mediated ACC-induced activation of SIMK and MMK3. Transgenic Arabidopsis plants overexpressing SIMKK have constitutive MPK6 activation and ethylene-induced target gene expression. SIMKK overexpressor lines resemble ctr1 mutants in showing a triple response phenotype in the absence of ACC. Whereas MPK6 was not activated by ACC in etr1 mutants, ein2 and ein3 mutants showed normal activation profiles. In contrast, ctr1 mutants showed constitutive activation of MPK6. These data indicate that a MAPK cascade is part of the ethylene signal transduction pathway in plants.
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PMID:A MAPK pathway mediates ethylene signaling in plants. 1262 21

Ethylene hormone responses are negatively regulated by the CTR1 protein, which has similarity to mitogen-activated protein kinase kinase kinases (MAPKKKs). Because of this similarity, it has long been speculated that ethylene signal transduction involves a MAPK cascade. Now, a recent paper provides compelling evidence for an ethylene-activated MAPK pathway. The implication is that CTR1 and the newly identified MAPKK and MAPKs comprise a MAPK module that regulates ethylene responses in plants.
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PMID:Ethylene signaling: the MAPK module has finally landed. 1292 68

Ethylene, an important hormone in plant growth, development and response to environmental stimuli, is rapidly induced by mechanical injury or wounding. Although induction of ACS (1-aminocyclopropane-1-carboxylic acid synthase) gene expression has been associated with this process, the detailed regulatory mechanism is unclear. Here, we report that the wounding-induced ethylene production is modulated by both mitogen-activated protein kinase (MAPK) pathway and calcium-dependent protein kinase (CPK) pathway. Study using acs mutants demonstrated that four ACS isoforms, including ACS2, ACS6, ACS7 and ACS8, contribute to ethylene production in response to wounding. Loss-of-function analysis defines the role of MPK3 and MPK6, and their upstream MKK4 and MKK5, in wounding-induced ethylene production. They play an important role in the wounding-induced up-regulation of all four ACS genes expression. Independent of MAPK pathway, CPK5 and CPK6 are also involved in the wounding-induced ethylene production by regulating the expression of ACS2, ACS6 and ACS8 genes. Taken together, we demonstrate that two independent kinase signalling pathways, MPK3/MPK6 cascade and CPK5/CPK6, are involved in the wounding-induced ethylene biosynthesis via differential regulation of ACS genes at transcriptional level.
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PMID:Mitogen-activated protein kinases and calcium-dependent protein kinases are involved in wounding-induced ethylene biosynthesis in Arabidopsis thaliana. 2854 54