View source for 7xaf


==The crystal structure of TrkA kinase in complex with 4^6,14-dimethyl-N-(3-(4-methyl-1H-imidazol-1-yl)-5-(trifluoromethyl)phenyl)-10-oxo-5-oxa-11,14-diaza-1(3,6)-imidazo[1,2-b]pyridazina-4(1,3)-benzenacyclo- tetradecaphan-2-yne-45-carboxamide==
<StructureSection load='7xaf' size='340' side='right'caption='[[7xaf]], [[Resolution|resolution]] 3.00&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[7xaf]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=7XAF OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=7XAF FirstGlance]. <br>
</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">X-ray diffraction, [[Resolution|Resolution]] 3.001182&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=FKT:4^6,14-dimethyl-N-(3-(4-methyl-1H-imidazol-1-yl)-5-(trifluoromethyl)phenyl)-10-oxo-5-oxa-11,14-diaza-1(3,6)-imidazo[1,2-b]pyridazina-4(1,3)-benzenacyclo-tetradecaphan-2-yne-45-carboxamide'>FKT</scene></td></tr>
<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[https://proteopedia.org/fgij/fg.htm?mol=7xaf FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=7xaf OCA], [https://pdbe.org/7xaf PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=7xaf RCSB], [https://www.ebi.ac.uk/pdbsum/7xaf PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=7xaf ProSAT]</span></td></tr>
</table>
== Disease ==
[https://www.uniprot.org/uniprot/NTRK1_HUMAN NTRK1_HUMAN] Defects in NTRK1 are a cause of congenital insensitivity to pain with anhidrosis (CIPA) [MIM:[https://omim.org/entry/256800 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.<ref>PMID:8696348</ref> <ref>PMID:10090906</ref> <ref>PMID:10330344</ref> <ref>PMID:10233776</ref> <ref>PMID:10861667</ref> <ref>PMID:10982191</ref> <ref>PMID:10567924</ref> <ref>PMID:11310631</ref> <ref>PMID:11159935</ref> <ref>PMID:22302274</ref>   Defects in NTRK1 are a cause of thyroid papillary carcinoma (TPC) [MIM:[https://omim.org/entry/188550 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 ==
[https://www.uniprot.org/uniprot/NTRK1_HUMAN 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.<ref>PMID:1850821</ref> <ref>PMID:1849459</ref> <ref>PMID:8325889</ref> <ref>PMID:8155326</ref> <ref>PMID:11244088</ref> <ref>PMID:15488758</ref>   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.<ref>PMID:1850821</ref> <ref>PMID:1849459</ref> <ref>PMID:8325889</ref> <ref>PMID:8155326</ref> <ref>PMID:11244088</ref> <ref>PMID:15488758</ref> 
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
Tropomyosin receptor kinase (TRK) secondary mutations mediating acquired resistance, especially at the solvent-front (SF) and the DFG motif, represent an unmet clinical need. Small-molecule macrocyclic kinase inhibitors have displayed significant advantages in overcoming clinical resistance driven by kinase mutations; however, all reported small-molecule macrocyclic TRK inhibitors are all type I inhibitors and are therefore much more sensitive to SF than xDFG mutations. Novel therapeutics for patients with xDFG resistance mutations are urgently needed. We report the first highly selective macrocycle-based potent type II TRK inhibitor, 7b, that exhibits high inhibitory potency toward various TRK fusion protein variants as well as wild type. 7b exhibited potent antiproliferative activity against Ba/F3 cells harboring CD74-TRKA(G667C) and ETV6-TRKC(G696C) with half-maximum inhibitory concentration (IC(50)) values of 6 and 1.7 nM, respectively. More importantly, 7b also showed potent antiproliferative activity against a panel of SF mutants (IC(50) = 5.6-110 nM) and displayed extraordinary kinome selectivity.

Discovery of the First Highly Selective and Broadly Effective Macrocycle-Based Type II TRK Inhibitors that Overcome Clinically Acquired Resistance.,Wang Z, Wang J, Wang Y, Xiang S, Song X, Tu Z, Zhou Y, Zhang ZM, Zhang Z, Ding K, Lu X J Med Chem. 2022 Apr 28;65(8):6325-6337. doi: 10.1021/acs.jmedchem.2c00308. Epub , 2022 Apr 15. PMID:35426680<ref>PMID:35426680</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 7xaf" style="background-color:#fffaf0;"></div>

==See Also==
*[[High affinity nerve growth factor receptor|High affinity nerve growth factor receptor]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Homo sapiens]]
[[Category: Large Structures]]
[[Category: Wang YJ]]
[[Category: Zhang ZM]]