6iqn | pdb_00006iqn

Crystal structure of TrkA kinase with ligand

spinqualitylabelsall models 6iqn, resolution 2.54Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 6iqn is a 2 chain structure. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Ligands: AQ6 Activity: Receptor protein-tyrosine kinase, with EC number 2.7.10.1 Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Disease [NTRK1_HUMAN] Defects in NTRK1 are a cause of congenital insensitivity to pain with anhidrosis (CIPA) [MIM:256800]. CIPA is characterized by a congenital insensitivity to pain, anhidrosis (absence of sweating), absence of reaction to noxious stimuli, self-mutilating behavior, and mental retardation. This rare autosomal recessive disorder is also known as congenital sensory neuropathy with anhidrosis or hereditary sensory and autonomic neuropathy type IV or familial dysautonomia type II. Defects in NTRK1 are a cause of thyroid papillary carcinoma (TPC) [MIM:188550]. TPC is a common tumor of the thyroid that typically arises as an irregular, solid or cystic mass from otherwise normal thyroid tissue. Papillary carcinomas are malignant neoplasm characterized by the formation of numerous, irregular, finger-like projections of fibrous stroma that is covered with a surface layer of neoplastic epithelial cells. Note=Chromosomal aberrations involving NTRK1 are found in thyroid papillary carcinomas. Translocation t(1;3)(q21;q11) with TFG generates the TRKT3 (TRK-T3) transcript by fusing TFG to the 3'-end of NTRK1; a rearrangement with TPM3 generates the TRK transcript by fusing TPM3 to the 3'-end of NTRK1; an intrachromosomal rearrangement that links the protein kinase domain of NTRK1 to the 5'-end of the TPR gene forms the fusion protein TRK-T1. TRK-T1 is a 55 kDa protein reacting with antibodies against the C-terminus of the NTRK1 protein. Function [NTRK1_HUMAN] Receptor tyrosine kinase involved in the development and the maturation of the central and peripheral nervous systems through regulation of proliferation, differentiation and survival of sympathetic and nervous neurons. High affinity receptor for NGF which is its primary ligand, it can also bind and be activated by NTF3/neurotrophin-3. However, NTF3 only supports axonal extension through NTRK1 but has no effect on neuron survival. Upon dimeric NGF ligand-binding, undergoes homodimerization, autophosphorylation and activation. Recruits, phosphorylates and/or activates several downstream effectors including SHC1, FRS2, SH2B1, SH2B2 and PLCG1 that regulate distinct overlapping signaling cascades driving cell survival and differentiation. Through SHC1 and FRS2 activates a GRB2-Ras-MAPK cascade that regulates cell differentiation and survival. Through PLCG1 controls NF-Kappa-B activation and the transcription of genes involved in cell survival. Through SHC1 and SH2B1 controls a Ras-PI3 kinase-AKT1 signaling cascade that is also regulating survival. In absence of ligand and activation, may promote cell death, making the survival of neurons dependent on trophic factors. Isoform TrkA-III is resistant to NGF, constitutively activates AKT1 and NF-kappa-B and is unable to activate the Ras-MAPK signaling cascade. Antagonizes the anti-proliferative NGF-NTRK1 signaling that promotes neuronal precursors differentiation. Isoform TrkA-III promotes angiogenesis and has oncogenic activity when overexpressed. Publication Abstract from PubMed The production of TrkA-selective inhibitors is considerably difficult because the kinase domains of TrkA and its isoforms TrkB/C have highly homologous amino acid sequences. Here we describe the structural basis for the acquisition of selectivity for a isoform-selective TrkA inhibitor, namely compound V1. The X-ray structure revealed that V1 acts as a molecular glue to stabilize the symmetrical dimer of the TrkA kinase domains. V1 binds to the ATP-binding site and simultaneously engages in the dimeric interface of TrkA. The region of the dimeric interface in TrkA is not conserved in TrkB/C; thus, dimer formation may be a novel mechanism for the production of selective TrkA inhibitors. The biochemical and biophysical assay results confirmed that V1 selectively inhibited TrkA and induced the dimer formation of TrkA, but not TrkB. The binding pocket at the TrkA dimer interface can be used for the production of new isoform-selective TrkA inhibitors. An isoform-selective inhibitor of tropomyosin receptor kinase A behaves as molecular glue.,Furuya N, Momose T, Katsuno K, Fushimi N, Muranaka H, Handa C, Sawa M, Ozawa T, Kinoshita T Bioorg Med Chem Lett. 2020 Jan 1;30(1):126775. doi: 10.1016/j.bmcl.2019.126775., Epub 2019 Oct 28. PMID:31699609 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

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