scholarly journals Mutation of the EPHA2 Tyrosine-Kinase Domain Dysregulates Cell Pattern Formation and Cytoskeletal Gene Expression in the Lens

Cells ◽  
2021 ◽  
Vol 10 (10) ◽  
pp. 2606
Author(s):  
Yuefang Zhou ◽  
Thomas M. Bennett ◽  
Philip A. Ruzycki ◽  
Alan Shiels
Keyword(s):  
Tyrosine Kinase ◽  
Ex Vivo ◽  
Missense Variant ◽  
Kinase Domain ◽  
Confocal Imaging ◽  
Fiber Cell ◽  
Tyrosine Kinase Domain ◽  
Sequencing Analysis ◽  
Fluorescent Reporter ◽  
Age Related

Genetic variations in ephrin type-A receptor 2 (EPHA2) have been associated with inherited and age-related forms of cataract in humans. Here, we have characterized the eye lens phenotype and transcript profile of germline Epha2 knock-in mutant mice homozygous for either a missense variant associated with age-related cataract in humans (Epha2-Q722) or a novel insertion-deletion mutation (Epha2-indel722) that were both located within the tyrosine-kinase domain of EPHA2. Confocal imaging of ex vivo lenses from Epha2-indel722 mice on a fluorescent reporter background revealed misalignment of epithelial-to-fiber cell meridional-rows at the lens equator and severe disturbance of Y-suture formation at the lens poles, whereas Epha2-Q722 lenses displayed mild disturbance of posterior sutures. Immunofluorescent labeling showed that EPHA2 was localized to radial columns of hexagonal fiber cell membranes in Epha2-Q722 lenses, whereas Epha2-indel722 lenses displayed disorganized radial cell columns and cytoplasmic retention of EPHA2. Immunoprecipitation/blotting studies indicated that EPHA2 formed strong complexes with Src kinase and was mostly serine phosphorylated in the lens. RNA sequencing analysis revealed differential expression of several cytoskeleton-associated genes in Epha2-mutant and Epha2-null lenses including shared downregulation of Lgsn and Clic5. Collectively, our data suggest that mutations within the tyrosine-kinase domain of EPHA2 result in lens cell patterning defects and dysregulated expression of several cytoskeleton-associated proteins.

BMS-354825 Is a SRC/ABL Inhibitor with High Nanomolar Activity Against the Kit D816v Mutation, Which Drives Systemic Mastocytosis and Is Imatinib-Resistant.

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 797-797 ◽  
Author(s):  
Neil P. Shah ◽  
Francis Y. Lee ◽  
Charles L. Sawyers ◽  
Cem Akin
Keyword(s):  
Tyrosine Kinase ◽  
Ex Vivo ◽  
Systemic Mastocytosis ◽  
Kinase Domain ◽  
Pharmacokinetic Analysis ◽  
Tyrosine Kinase Domain ◽  
Independent Manner ◽  
Kit Mutation ◽  
Imatinib Resistant

Abstract The vast majority of systemic mastocytosis cases are associated with a somatic KIT oncoprotein point mutation which substitutes a valine for aspartic acid (D816V), resulting in KIT receptor auto-phosphorylation in a ligand-independent manner. Previous reports have demonstrated that this mutation is inherently imatinib-resistant. Although interferon-alpha has some activity against aggressive systemic mastocytosis, major responses are uncommon, and the drug is associated with significant toxicity. To date, there remains no effective therapy for systemic mastocytosis. We recently described BMS-354825, a novel orally bioavailable SRC/ABL inhibitor that has activity against multiple imatinib-resistant BCR-ABL isoforms in vitro (Shah et al, Science 305:399, 2004). BMS-354825 is presently undergoing evaluation in a phase I clinical trial of imatinib-resistant CML patients, and is showing signs of clinical efficacy. Pharmacokinetic analysis suggests that high nanomolar concentrations of the compound can be safely achieved in humans (see Sawyers et al, Talpaz et al, abstracts submitted for this meeting). To determine if this compound warrants study in other human hematologic conditions, we tested BMS-354825 for activity against human mastocytosis cell lines HMC-1560 and HMC-1560,816, carrying an activating c-kit mutation in juxtamembrane domain (codon 560) with or without a second mutation in tyrosine kinase domain (codon 816), respectively. While 1 um imatinib failed to inhibit the growth of HMC-1560,816 cells carrying the tyrosine kinase domain c-kit mutation, BMS-354825 led to an almost complete growth inhibition at the same concentration, with an IC50 of 0.1–1 uM. In addition, growth of HMC-1560 cells carrying the juxtamembrane c-kit mutation alone was more effectively inhibited by BMS-354825 as compared to imatinib (IC50 of <0.01 vs 0.01–0.1 micromolars respectively). Significantly, detection of phospho-KIT by Western blot analysis was significantly reduced in the presence of BMS-354825 at nanomolar concentrations. An ex vivo assessment of D816V-harboring mast cell sensitivity using a flow cytometric method in systemic mastocytosis bone marrow samples is ongoing. Our findings suggest that studies to evaluate BMS-354825 for the treatment of systemic mastocytosis are warranted. Additionally, the compound may harbor activity in other disease settings that contain activating KIT mutations.

NIDDM associated with mutation in tyrosine kinase domain of insulin receptor gene

Diabetes ◽  
1992 ◽  
Vol 41 (4) ◽  
pp. 521-526 ◽  
Author(s):  
S. Cocozza ◽  
A. Porcellini ◽  
G. Riccardi ◽  
A. Monticelli ◽  
G. Condorelli ◽  
...  
Keyword(s):  
Tyrosine Kinase ◽  
Insulin Receptor ◽  
Receptor Gene ◽  
Kinase Domain ◽  
Tyrosine Kinase Domain ◽  
Insulin Receptor Gene

scholarly journals Characterization of Atypical Protein Tyrosine Kinase (PTK) Genes and Their Role in Abiotic Stress Response in Rice

Plants ◽  
2020 ◽  
Vol 9 (5) ◽  
pp. 664
Author(s):  
Allimuthu Elangovan ◽  
Monika Dalal ◽  
Gopinathan Kumar Krishna ◽  
Sellathdurai Devika ◽  
Ranjeet Ranjan Kumar ◽  
...  
Keyword(s):  
Abiotic Stress ◽  
Stress Response ◽  
Tyrosine Kinase ◽  
Tyrosine Phosphorylation ◽  
Rice Genome ◽  
Kinase Domain ◽  
Tyrosine Kinase Domain ◽  
Protein Tyrosine ◽  
Dual Specificity ◽  
Submergence Stress

Tyrosine phosphorylation constitutes up to 5% of the total phophoproteome. However, only limited studies are available on protein tyrosine kinases (PTKs) that catalyze protein tyrosine phosphorylation in plants. In this study, domain analysis of the 27 annotated PTK genes in rice genome led to the identification of 18 PTKs with tyrosine kinase domain. The kinase domain of rice PTKs shared high homology with that of dual specificity kinase BRASSINOSTEROID-INSENSITIVE 1 (BRI1) of Arabidopsis. In phylogenetic analysis, rice PTKs clustered with receptor-like cytoplasmic kinases-VII (RLCKs-VII) of Arabidopsis. mRNAseq analysis using Genevestigator revealed that rice PTKs except PTK9 and PTK16 express at moderate to high level in most tissues. PTK16 expression was highly abundant in panicle at flowering stage. mRNAseq data analysis led to the identification of drought, heat, salt, and submergence stress regulated PTK genes in rice. PTK14 was upregulated under all stresses. qRT-PCR analysis also showed that all PTKs except PTK10 were significantly upregulated in root under osmotic stress. Tissue specificity and abiotic stress mediated differential regulation of PTKs suggest their potential role in development and stress response of rice. The candidate dual specificity PTKs identified in this study paves way for molecular analysis of tyrosine phosphorylation in rice.

scholarly journals Directed Discovery of Agents Targeting the Met Tyrosine Kinase Domain by Virtual Screening

2009 ◽  
Vol 52 (4) ◽  
pp. 943-951 ◽  
Author(s):  
Megan L. Peach ◽  
Nelly Tan ◽  
Sarah J. Choyke ◽  
Alessio Giubellino ◽  
Gagani Athauda ◽  
...  
Keyword(s):  
Virtual Screening ◽  
Tyrosine Kinase ◽  
Kinase Domain ◽  
Tyrosine Kinase Domain

A recurrent mutation in the tyrosine kinase domain of fibroblast growth factor receptor 3 causes hypochondroplasia

1995 ◽  
Vol 10 (3) ◽  
pp. 357-359 ◽  
Author(s):  
Gary A. Bellus ◽  
Iain McIntosh ◽  
E. Anne Smith ◽  
Arthur S. Aylsworth ◽  
Ilkka Kaitila ◽  
...  
Keyword(s):  
Growth Factor ◽  
Tyrosine Kinase ◽  
Fibroblast Growth Factor ◽  
Fibroblast Growth Factor Receptor ◽  
Growth Factor Receptor ◽  
Kinase Domain ◽  
Recurrent Mutation ◽  
Tyrosine Kinase Domain ◽  
Fibroblast Growth

Expanding the search for significant EGFR mutations in NSCLC outside of the tyrosine kinase domain with next-generation sequencing

2017 ◽  
Vol 34 (7) ◽  
Author(s):  
Matthew K. Stein ◽  
Lindsay Morris ◽  
Jennifer L. Sullivan ◽  
Moon Fenton ◽  
Ari VanderWalde ◽  
...  
Keyword(s):  
Next Generation Sequencing ◽  
Tyrosine Kinase ◽  
Kinase Domain ◽  
Egfr Mutations ◽  
Tyrosine Kinase Domain ◽  
Next Generation ◽  
Generation Sequencing

scholarly journals Regulation of Jak2 Function by Phosphorylation of Tyr317 and Tyr637 during Cytokine Signaling

2009 ◽  
Vol 29 (12) ◽  
pp. 3367-3378 ◽  
Author(s):  
Scott A. Robertson ◽  
Rositsa I. Koleva ◽  
Lawrence S. Argetsinger ◽  
Christin Carter-Su ◽  
Jarrod A. Marto ◽  
...  
Keyword(s):  
Tyrosine Kinase ◽  
Kinase Activity ◽  
Feedback Inhibition ◽  
Dominant Role ◽  
Kinase Domain ◽  
Cytokine Signaling ◽  
Tyrosine Kinase Domain ◽  
Phosphorylation Sites ◽  
Cytokine Stimulation

ABSTRACT Jak2, the cognate tyrosine kinase for numerous cytokine receptors, undergoes multisite phosphorylation during cytokine stimulation. To understand the role of phosphorylation in Jak2 regulation, we used mass spectrometry to identify numerous Jak2 phosphorylation sites and characterize their significance for Jak2 function. Two sites outside of the tyrosine kinase domain, Tyr317 in the FERM domain and Tyr637 in the JH2 domain, exhibited strong regulation of Jak2 activity. Mutation of Tyr317 promotes increased Jak2 activity, and the phosphorylation of Tyr317 during cytokine signaling requires prior activation loop phosphorylation, which is consistent with a role for Tyr317 in the feedback inhibition of Jak2 kinase activity after receptor stimulation. Comparison to several previously identified regulatory phosphorylation sites on Jak2 revealed a dominant role for Tyr317 in the attenuation of Jak2 signaling. In contrast, mutation of Tyr637 decreased Jak2 signaling and activity and partially suppressed the activating JH2 V617F mutation, suggesting a role for Tyr637 phosphorylation in the release of JH2 domain-mediated suppression of Jak2 kinase activity during cytokine stimulation. The phosphorylation of Tyr317 and Tyr637 act in concert with other regulatory events to maintain appropriate control of Jak2 activity and cytokine signaling.

Functional dissection of p56lck, a protein tyrosine kinase which mediates interleukin-2-induced activation of the c-fos gene

1994 ◽  
Vol 14 (9) ◽  
pp. 5812-5819
Author(s):  
H Shibuya ◽  
K Kohu ◽  
K Yamada ◽  
E L Barsoumian ◽  
R M Perlmutter ◽  
...  
Keyword(s):  
Tyrosine Kinase ◽  
Tyrosine Kinases ◽  
Protein Tyrosine Kinase ◽  
Gene Activation ◽  
Interleukin 2 ◽  
Kinase Domain ◽  
Tyrosine Kinase Domain ◽  
Amino Acid Residues ◽  
Protein Tyrosine ◽  
Responsive Element

Members of the newly identified receptor family for cytokines characteristically lack the intrinsic protein tyrosine kinase domain that is a hallmark of other growth factor receptors. Instead, accumulating evidence suggests that these receptors utilize nonreceptor-type protein tyrosine kinases for downstream signal transduction by cytokines. We have shown previously that the interleukin-2 receptor beta-chain interacts both physically and functionally with a Src family member, p56lck, and that p56lck activation leads to induction of the c-fos gene. However, the mechanism linking p56lck activation with c-fos induction remains unelucidated. In the present study, we systematically examined the extent of c-fos promoter activation by expression of a series of p56lck mutants, using a transient cotransfection assay. The results define a set of the essential amino acid residues that regulate p56lck induction of the c-fos promoter. We also provide evidence that the serum-responsive element and sis-inducible element are both targets through which p56lck controls c-fos gene activation.

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