3aln
From Proteopedia
Crystal Structure of human non-phosphorylated MKK4 kinase domain complexed with AMP-PNP
Structural highlights
Function[MP2K4_HUMAN] Dual specificity protein kinase which acts as an essential component of the MAP kinase signal transduction pathway. Essential component of the stress-activated protein kinase/c-Jun N-terminal kinase (SAP/JNK) signaling pathway. With MAP2K7/MKK7, is the one of the only known kinase to directly activate the stress-activated protein kinase/c-Jun N-terminal kinases MAPK8/JNK1, MAPK9/JNK2 and MAPK10/JNK3. MAP2K4/MKK4 and MAP2K7/MKK7 both activate the JNKs by phosphorylation, but they differ in their preference for the phosphorylation site in the Thr-Pro-Tyr motif. MAP2K4 shows preference for phosphorylation of the Tyr residue and MAP2K7/MKK7 for the Thr residue. The phosphorylation of the Thr residue by MAP2K7/MKK7 seems to be the prerequisite for JNK activation at least in response to proinflammatory cytokines, while other stimuli activate both MAP2K4/MKK4 and MAP2K7/MKK7 which synergistically phosphorylate JNKs. MAP2K4 is required for maintaining peripheral lymphoid homeostasis. The MKK/JNK signaling pathway is also involved in mitochondrial death signaling pathway, including the release cytochrome c, leading to apoptosis. Whereas MAP2K7/MKK7 exclusively activates JNKs, MAP2K4/MKK4 additionally activates the p38 MAPKs MAPK11, MAPK12, MAPK13 and MAPK14.[1] Publication Abstract from PubMedMKK4 activates both JNKs and p38s. We determined the crystal structures of human non-phosphorylated MKK4 kinase domain (npMKK4) complexed with AMP-PNP (npMKK4/AMP) and a ternary complex of npMKK4, AMP-PNP and p38alpha peptide (npMKK4/AMP/p38). These crystal structures revealed that the p38alpha peptide-bound npMKK4 at the allosteric site rather than at the putative substrate binding site and induced an auto-inhibition state. While the activation loop of the npMKK4/AMP complex was disordered, in the npMKK4/AMP/p38 complex it configured a long alpha-helix, which prevented substrate access to the active site and alphaC-helix movement to the active configuration of MKK4. Crystal structures of MKK4 kinase domain reveal that substrate peptide binds to an allosteric site and induces an auto-inhibition state.,Matsumoto T, Kinoshita T, Kirii Y, Yokota K, Hamada K, Tada T Biochem Biophys Res Commun. 2010 Sep 24;400(3):369-73. Epub 2010 Aug 21. PMID:20732303[2] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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