3q6u
Structure of the apo MET receptor kinase in the dually-phosphorylated, activated state
Structural highlights
DiseaseMET_HUMAN Note=Activation of MET after rearrangement with the TPR gene produces an oncogenic protein. Note=Defects in MET may be associated with gastric cancer. Defects in MET are a cause of hepatocellular carcinoma (HCC) [MIM:114550.[1] Defects in MET are a cause of renal cell carcinoma papillary (RCCP) [MIM:605074. It is a subtype of renal cell carcinoma tending to show a tubulo-papillary architecture formed by numerous, irregular, finger-like projections of connective tissue. Renal cell carcinoma is a heterogeneous group of sporadic or hereditary carcinoma derived from cells of the proximal renal tubular epithelium. It is subclassified into common renal cell carcinoma (clear cell, non-papillary carcinoma), papillary renal cell carcinoma, chromophobe renal cell carcinoma, collecting duct carcinoma with medullary carcinoma of the kidney, and unclassified renal cell carcinoma.[2] [3] [4] [5] [6] Note=A common allele in the promoter region of the MET shows genetic association with susceptibility to autism in some families. Functional assays indicate a decrease in MET promoter activity and altered binding of specific transcription factor complexes. Note=MET activating mutations may be involved in the development of a highly malignant, metastatic syndrome known as cancer of unknown primary origin (CUP) or primary occult malignancy. Systemic neoplastic spread is generally a late event in cancer progression. However, in some instances, distant dissemination arises at a very early stage, so that metastases reach clinical relevance before primary lesions. Sometimes, the primary lesions cannot be identified in spite of the progresses in the diagnosis of malignancies.[7] FunctionMET_HUMAN Receptor tyrosine kinase that transduces signals from the extracellular matrix into the cytoplasm by binding to hepatocyte growth factor/HGF ligand. Regulates many physiological processes including proliferation, scattering, morphogenesis and survival. Ligand binding at the cell surface induces autophosphorylation of MET on its intracellular domain that provides docking sites for downstream signaling molecules. Following activation by ligand, interacts with the PI3-kinase subunit PIK3R1, PLCG1, SRC, GRB2, STAT3 or the adapter GAB1. Recruitment of these downstream effectors by MET leads to the activation of several signaling cascades including the RAS-ERK, PI3 kinase-AKT, or PLCgamma-PKC. The RAS-ERK activation is associated with the morphogenetic effects while PI3K/AKT coordinates prosurvival effects. During embryonic development, MET signaling plays a role in gastrulation, development and migration of muscles and neuronal precursors, angiogenesis and kidney formation. In adults, participates in wound healing as well as organ regeneration and tissue remodeling. Promotes also differentiation and proliferation of hematopoietic cells.[8] [9] [10] Acts as a receptor for Listeria internalin inlB, mediating entry of the pathogen into cells.[11] [12] [13] Publication Abstract from PubMedThe receptor tyrosine kinase c-Met is implicated in oncogenesis and is the target for several small molecule and biologic agents in clinical trials for the treatment of cancer. Binding of the hepatocyte growth factor to the cell surface receptor of c-Met induces activation via autophosphorylation of the kinase domain. Here we describe the structural basis of c-Met activation upon autophosphorylation and the selective small molecule inhibiton of autophosphorylated c-Met. MK-2461 is a potent c-Met inhibitor that is selective for the phosphorylated state of the enzyme. Compound 1 is an MK-2461 analog with a 20-fold enthalpy-driven preference for the autophosphorylated over unphosphorylated c-Met kinase domain. The crystal structure of the unbound kinase domain phosphorylated at Tyr-1234 and Tyr-1235 shows that activation loop phosphorylation leads to the ejection and disorder of the activation loop and rearrangement of helix alphaC and the G loop to generate a viable active site. Helix alphaC adopts a orientation different from that seen in activation loop mutants. The crystal structure of the complex formed by the autophosphorylated c-Met kinase domain and compound 1 reveals a significant induced fit conformational change of the G loop and ordering of the activation loop, explaining the selectivity of compound 1 for the autophosphorylated state. The results highlight the role of structural plasticity within the kinase domain in imparting the specificity of ligand binding and provide the framework for structure-guided design of activated c-Met inhibitors. Structural basis for selective small molecule kinase inhibition of activated c-Met.,Rickert KW, Patel SB, Allison TJ, Byrne NJ, Darke PL, Ford RE, Guerin DJ, Hall DL, Kornienko M, Lu J, Munshi SK, Reid JC, Shipman JM, Stanton EF, Wilson KJ, Young JR, Soisson SM, Lumb KJ J Biol Chem. 2011 Apr 1;286(13):11218-25. Epub 2011 Jan 18. PMID:21247903[14] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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