4pgz | pdb_00004pgz

Structural basis of KIT activation by oncogenic mutations in the extracellular region reveals a zipper-like mechanism for ligand-dependent or oncogenic receptor tyrosine kinase activation

spinqualitylabelsall models 4pgz, resolution 2.40Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 4pgz is a 3 chain structure with sequence from Homo sapiens. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 2.4Å Ligands: CO, NAG Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Disease KIT_HUMAN Defects in KIT are a cause of piebald trait (PBT) [MIM:172800; also known as piebaldism. PBT is an autosomal dominant genetic developmental abnormality of pigmentation characterized by congenital patches of white skin and hair that lack melanocytes. Defects in KIT are a cause of gastrointestinal stromal tumor (GIST) [MIM:606764. Defects in KIT have been associated with testicular germ cell tumor (TGCT) [MIM:273300. A common solid malignancy in males. Germ cell tumors of the testis constitute 95% of all testicular neoplasms. Defects in KIT are a cause of acute myelogenous leukemia (AML) [MIM:601626. AML is a malignant disease in which hematopoietic precursors are arrested in an early stage of development. Note=Somatic mutations that lead to constitutive activation of KIT are detected in AML patients. These mutations fall into two classes, the most common being in-frame internal tandem duplications of variable length in the juxtamembrane region that disrupt the normal regulation of the kinase activity. Likewise, point mutations in the kinase domain can result in a constitutively activated kinase. Function KIT_HUMAN Tyrosine-protein kinase that acts as cell-surface receptor for the cytokine KITLG/SCF and plays an essential role in the regulation of cell survival and proliferation, hematopoiesis, stem cell maintenance, gametogenesis, mast cell development, migration and function, and in melanogenesis. In response to KITLG/SCF binding, KIT can activate several signaling pathways. Phosphorylates PIK3R1, PLCG1, SH2B2/APS and CBL. Activates the AKT1 signaling pathway by phosphorylation of PIK3R1, the regulatory subunit of phosphatidylinositol 3-kinase. Activated KIT also transmits signals via GRB2 and activation of RAS, RAF1 and the MAP kinases MAPK1/ERK2 and/or MAPK3/ERK1. Promotes activation of STAT family members STAT1, STAT3, STAT5A and STAT5B. Activation of PLCG1 leads to the production of the cellular signaling molecules diacylglycerol and inositol 1,4,5-trisphosphate. KIT signaling is modulated by protein phosphatases, and by rapid internalization and degradation of the receptor. Activated KIT promotes phosphorylation of the protein phosphatases PTPN6/SHP-1 and PTPRU, and of the transcription factors STAT1, STAT3, STAT5A and STAT5B. Promotes phosphorylation of PIK3R1, CBL, CRK (isoform Crk-II), LYN, MAPK1/ERK2 and/or MAPK3/ERK1, PLCG1, SRC and SHC1. Publication Abstract from PubMed The receptor tyrosine kinase KIT plays an important role in development of germ cells, hematopoietic cells, and interstitial pacemaker cells. Oncogenic KIT mutations play an important "driver" role in gastrointestinal stromal tumors, acute myeloid leukemias, and melanoma, among other cancers. Here we describe the crystal structure of a recurring somatic oncogenic mutation located in the C-terminal Ig-like domain (D5) of the ectodomain, rendering KIT tyrosine kinase activity constitutively activated. The structural analysis, together with biochemical and biophysical experiments and detailed analyses of the activities of a variety of oncogenic KIT mutations, reveals that the strength of homotypic contacts and the cooperativity in the action of D4D5 regions determines whether KIT is normally regulated or constitutively activated in cancers. We propose that cooperative interactions mediated by multiple weak homotypic contacts between receptor molecules are responsible for regulating normal ligand-dependent or oncogenic RTK activation via a "zipper-like" mechanism for receptor activation. The strength and cooperativity of KIT ectodomain contacts determine normal ligand-dependent stimulation or oncogenic activation in cancer.,Reshetnyak AV, Opatowsky Y, Boggon TJ, Folta-Stogniew E, Tome F, Lax I, Schlessinger J Mol Cell. 2015 Jan 8;57(1):191-201. doi: 10.1016/j.molcel.2014.11.021. Epub 2014 , Dec 24. PMID:25544564 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Tyrosine kinase 3D structures

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