5k5x
From Proteopedia
Crystal structure of human PDGFRA
Structural highlights
DiseasePGFRA_HUMAN Myeloid neoplasm associated with PDGFRA rearrangement;Primary hypereosinophilic syndrome;Precursor B-cell acute lymphoblastic leukemia;Gastrointestinal stromal tumor. A chromosomal aberration involving PDGFRA is found in some cases of hypereosinophilic syndrome. Interstitial chromosomal deletion del(4)(q12q12) causes the fusion of FIP1L1 and PDGFRA (FIP1L1-PDGFRA). Mutations that cause overexpression and/or constitutive activation of PDGFRA may be a cause of hypereosinophilic syndrome.[1] The gene represented in this entry may be involved in disease pathogenesis. Mutations causing PDGFRA constitutive activation have been found in gastrointestinal stromal tumors lacking KIT mutations (PubMed:12522257).[2] FunctionPGFRA_HUMAN Tyrosine-protein kinase that acts as a cell-surface receptor for PDGFA, PDGFB and PDGFC and plays an essential role in the regulation of embryonic development, cell proliferation, survival and chemotaxis. Depending on the context, promotes or inhibits cell proliferation and cell migration. Plays an important role in the differentiation of bone marrow-derived mesenchymal stem cells. Required for normal skeleton development and cephalic closure during embryonic development. Required for normal development of the mucosa lining the gastrointestinal tract, and for recruitment of mesenchymal cells and normal development of intestinal villi. Plays a role in cell migration and chemotaxis in wound healing. Plays a role in platelet activation, secretion of agonists from platelet granules, and in thrombin-induced platelet aggregation. Binding of its cognate ligands - homodimeric PDGFA, homodimeric PDGFB, heterodimers formed by PDGFA and PDGFB or homodimeric PDGFC -leads to the activation of several signaling cascades; the response depends on the nature of the bound ligand and is modulated by the formation of heterodimers between PDGFRA and PDGFRB. Phosphorylates PIK3R1, PLCG1, and PTPN11. Activation of PLCG1 leads to the production of the cellular signaling molecules diacylglycerol and inositol 1,4,5-trisphosphate, mobilization of cytosolic Ca(2+) and the activation of protein kinase C. Phosphorylates PIK3R1, the regulatory subunit of phosphatidylinositol 3-kinase, and thereby mediates activation of the AKT1 signaling pathway. Mediates activation of HRAS and of the MAP kinases MAPK1/ERK2 and/or MAPK3/ERK1. Promotes activation of STAT family members STAT1, STAT3 and STAT5A and/or STAT5B. Receptor signaling is down-regulated by protein phosphatases that dephosphorylate the receptor and its down-stream effectors, and by rapid internalization of the activated receptor.[3] [4] [5] [6] [7] [8] [9] [10] [11] [12] [13] [14] [15] [16] Publication Abstract from PubMedPlatelet-derived growth factor receptor alpha (PDGFRA) is a Type III receptor tyrosine kinase, and this kinase is a target for treatment of gastrointestinal stromal tumors (GIST) as it is frequently mutated in these cancers. Most of the mutations that cause constitutive activation of PDGFRA occur in either the activation loop (A-loop) or in the juxtamembrane (JM) domain, such as the mutations D842V or V561D respectively. Treatment of PDGFRA-mutated GIST with imatinib is successful in some cases, but the D842V mutation is imatinib-resistant. To better understand the mechanism of PDGFRA drug-resistance, we have determined the crystal structure of the PDGFRA kinase domain in the auto-inhibited form, and studied the kinetics of the D842V mutation. Auto-inhibited PDGFRA is stabilized by the JM domain, which inserts into the active site of the kinase. The conserved residue Asp842 makes extensive contacts with several A-loop residues to maintain PDGFRA in the "DFG out" conformation, which stabilizes the kinase in the inactive state and facilitates the binding of imatinib. The D842V mutation would therefore be expected to activate the kinase and hinder the binding of drug through destabilizing the "DFG out" conformation. Furthermore, our kinetic data show that drug resistance in the D842V mutation may also in part result from its increased affinity for ATP. The PDGFRA kinase domain structure we report in this study has potential to facilitate development of new agents which can inhibit this kinase, including both its activating and drug-resistant mutations. Structural and biochemical studies of the PDGFRA kinase domain.,Liang L, Yan XE, Yin Y, Yun CH Biochem Biophys Res Commun. 2016 Sep 2;477(4):667-72. doi:, 10.1016/j.bbrc.2016.06.117. Epub 2016 Jun 24. PMID:27349873[17] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. Loading citation details.. Citations No citations found References
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