4tt7
From Proteopedia
Crystal structure of human ALK with a covalent modification
Structural highlights
Disease[ALK_HUMAN] Note=A chromosomal aberration involving ALK is found in a form of non-Hodgkin lymphoma. Translocation t(2;5)(p23;q35) with NPM1. The resulting chimeric NPM1-ALK protein homodimerize and the kinase becomes constitutively activated. The constitutively active fusion proteins are responsible for 5-10% of non-Hodgkin lymphomas. Note=A chromosomal aberration involving ALK is associated with inflammatory myofibroblastic tumors (IMTs). Translocation t(2;11)(p23;p15) with CARS; translocation t(2;4)(p23;q21) with SEC31A. Note=A chromosomal aberration involving ALK is associated with anaplastic large-cell lymphoma (ALCL). Translocation t(2;17)(p23;q25) with ALO17. Defects in ALK are the cause of susceptibility to neuroblastoma type 3 (NBLST3) [MIM:613014]. Neuroblastoma is a common neoplasm of early childhood arising from embryonic cells that form the primitive neural crest and give rise to the adrenal medulla and the sympathetic nervous system.[1] [2] [3] Note=The ALK signaling pathway plays an important role in glioblastoma, the most common malignant brain tumor of adults and one of the most lethal cancers. It regulates both glioblastoma migration and growth. Function[ALK_HUMAN] Neuronal orphan receptor tyrosine kinase that is essentially and transiently expressed in specific regions of the central and peripheral nervous systems and plays an important role in the genesis and differentiation of the nervous system. Transduces signals from ligands at the cell surface, through specific activation of the mitogen-activated protein kinase (MAPK) pathway. Phosphorylates almost exclusively at the first tyrosine of the Y-x-x-x-Y-Y motif. Following activation by ligand, ALK induces tyrosine phosphorylation of CBL, FRS2, IRS1 and SHC1, as well as of the MAP kinases MAPK1/ERK2 and MAPK3/ERK1. Acts as a receptor for ligands pleiotrophin (PTN), a secreted growth factor, and midkine (MDK), a PTN-related factor, thus participating in PTN and MDK signal transduction. PTN-binding induces MAPK pathway activation, which is important for the anti-apoptotic signaling of PTN and regulation of cell proliferation. MDK-binding induces phosphorylation of the ALK target insulin receptor substrate (IRS1), activates mitogen-activated protein kinases (MAPKs) and PI3-kinase, resulting also in cell proliferation induction. Drives NF-kappa-B activation, probably through IRS1 and the activation of the AKT serine/threonine kinase. Recruitment of IRS1 to activated ALK and the activation of NF-kappa-B are essential for the autocrine growth and survival signaling of MDK.[4] [5] [6] [7] [8] [9] [10] [11] [12] [13] [14] Publication Abstract from PubMedBNP7787 (Tavocept, disodium 2,2'-dithio-bis-ethanesulfonate) is a novel, investigational, water-soluble disulfide that is well-tolerated and nontoxic. In separate randomized multicenter Phase II and Phase III clinical trials in non-small-cell lung cancer (NSCLC) patients, treatment with BNP7787 in combination with standard chemotherapy resulted in substantial increases in the overall survival of patients with advanced adenocarcinoma of the lung in the first-line treatment setting. We hypothesized that BNP7787 might interact with and modify human anaplastic lymphoma kinase (ALK). At least seven different variants of ALK fusions with the gene encoding the echinoderm microtubule-associated protein-like 4 (EML4) are known to occur in NSCLC. EML4-ALK fusions are thought to account for approximately 3% of NSCLC cases. Herein, we report the covalent modification of the kinase domain of human ALK by a BNP7787-derived mesna moiety and the functional consequences of this modification in ALK assays evaluating kinase activity. The kinase domain of the ALK protein crystallizes as a monomer, and BNP7787-derived mesna-cysteine adducts were observed at Cys 1235 and Cys 1156. The BNP7787-derived mesna adduct at Cys 1156 is located in close proximity to the active site and results in substantial disorder of the P-loop and activation loop (A-loop). Comparison with the P-loop of apo-ALK suggests that the BNP7787-derived mesna adduct at Cys 1156 interferes with the positioning of Phe 1127 into a small pocket now occupied by mesna, resulting in a destabilization of the loop's binding orientation. Additionally, in vitro kinase activity assays indicate that BNP7787 inhibits ALK catalytic activity and potentiates the activity of the ALK-targeted drug crizotinib. Novel covalent modification of human anaplastic lymphoma kinase (ALK) and potentiation of crizotinib-mediated inhibition of ALK activity by BNP7787.,Parker AR, Petluru PN, Nienaber VL, Zhao M, Ayala PY, Badger J, Chie-Leon B, Sridhar V, Logan C, Kochat H, Hausheer FH Onco Targets Ther. 2015 Feb 4;8:375-83. doi: 10.2147/OTT.S73690. eCollection, 2015. PMID:25678804[15] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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