Disease relevance of ATMPK1

• Purified Xenopus MAP kinase kinase (MAPK kinase) phosphorylates ATMPK1 and ATMPK2 proteins that have been expressed in Escherichia coli, activating these enzymes [1].
• RNA interference-based (RNAi) suppression of AtMPK6, an Arabidopsis mitogen-activated protein kinase, results in hypersensitivity to ozone and misregulation of AtMPK3 [2].

High impact information on ATMPK1

• Moreover, the effects of NPK1 on the activation of a MAPK and the repression of early auxin response gene transcription are specifically eliminated by a MAPK phosphatase [3].
• Suppression of auxin signal transduction by a MAPK cascade in higher plants [3].
• Mitogen-activated protein kinase phosphatase is required for genotoxic stress relief in Arabidopsis [4].
• Molecular genetic analysis indicated that the bud1 phenotype is a result of increased expression of Arabidopsis MAP KINASE KINASE7 (MKK7), a member of plant mitogen-activated protein kinase kinase group D. We showed that BUD1/MKK7 is a functional kinase and that the kinase activity is essential for its biological functions [5].
• Phosphorylation of 1-aminocyclopropane-1-carboxylic acid synthase by MPK6, a stress-responsive mitogen-activated protein kinase, induces ethylene biosynthesis in Arabidopsis [6].

Biological context of ATMPK1

• The amino acid residues corresponding to the sites of phosphorylation (Thr-Glu-Tyr) that are involved in the activation of MAP kinases are conserved in ATMPK1 and ATMPK2 [1].
• Genomic Southern blot analysis suggests that there are a few additional genes that are related to ATMPK1 and ATMPK2 in the Arabidopsis genome [1].
• Silencing of the mitogen-activated protein kinase MPK6 compromises disease resistance in Arabidopsis [7].
• Connecting oxidative stress, auxin, and cell cycle regulation through a plant mitogen-activated protein kinase pathway [8].
• Raf is part of a mitogen-activated protein kinase cascade known to regulate cell growth and development in mammals, worms, and flies [9].

Anatomical context of ATMPK1

• We propose that the PHS1 phosphatase regulates more than one MAPK and that a subset of its target kinases is involved in the organization of cortical microtubules [10].
• The endogenous Arabidopsis MAP kinase kinase MKK1 is activated in cells treated with flg22, phosphorylates the MAPK MPK4 in vitro, and activates it in vivo in protoplasts [11].
• We analysed effect of oxidative stress on the activation of ATMPK6, an Arabidopsis thaliana MAPK, in Arabidopsis T87 cultured cells and rosette leaves using anti-ATMPK6 specific antibody [12].

Associations of ATMPK1 with chemical compounds

• These results suggest that auxin sensitivity may be balanced by antagonistic signalling pathways that use a distinct MAPK cascade in higher plants [3].
• We have identified an Arabidopsis mutant (mkp1) hypersensitive to genotoxic stress treatments (UV-C and methyl methanesulphonate) due to disruption of a gene that encodes an Arabidopsis homolog of mitogen-activated protein kinase phosphatase (AtMKP1) [4].
• Mitogen-activated protein kinase signaling in postgermination arrest of development by abscisic acid [13].
• Making use of the ABA-hypersensitive hyl1 mutant of Arabidopsis, we show that the ABA signal is transmitted to the transcriptional apparatus through mitogen-activated protein kinase signaling [13].
• Two of the receptors have been found to associate with a negative regulator of ethylene responses called CTR1, which appears to be a mitogen-activated protein kinase (MAPK) kinase kinase [14].

Regulatory relationships of ATMPK1

• SCD1 is a unique gene in Arabidopsis that encodes a protein related to animal proteins that regulate intracellular protein transport and/or mitogen-activated protein kinase signaling pathways [15].
• The activation of the RD29A promoter correlated with four uniquely activated AtMPK proteins [16].

Other interactions of ATMPK1

• ATMPK1 and ATMPK2 exhibit significant similarity to rat ERK2 (49%) and Xenopus MAP kinase (50%) [1].
• Introduction of the ATHK1 cDNA into the yeast double mutant sln1Delta sho1Delta, which lacks two osmosensors, suppressed lethality in high-salinity media and activated the high-osmolarity glycerol response 1 (HOG1) mitogen-activated protein kinase (MAPK) [17].
• Stress-induced protein phosphatase 2C is a negative regulator of a mitogen-activated protein kinase [18].
• ATMPK4, an Arabidopsis homolog of mitogen-activated protein kinase, is activated in vitro by AtMEK1 through threonine phosphorylation [19].
• Sequence similarity between CTR1 and the Raf protein kinases implies involvement of a mitogen-activated protein kinase cascade in this signaling pathway [20].

Analytical, diagnostic and therapeutic context of ATMPK1

• Northern blot analysis indicates that the ATMPK1 and ATMPK2 mRNAs are significantly present in all the organs except seeds [1].
• Here, we show that a rice (Oryza sativa) MAPK, OsMAPK6, was posttranslationally activated in a cell culture by a sphingolipid elicitor [21].
• Molecular cloning and mRNA expression analysis of a novel rice (Oryzasativa L.) MAPK kinase kinase, OsEDR1, an ortholog of Arabidopsis AtEDR1, reveal its role in defense/stress signalling pathways and development [22].

References