scholarly journals Screening and Functional Analysis of TEK Mutations in Chinese Children With Primary Congenital Glaucoma

2021 ◽  
Vol 12 ◽  
Author(s):  
Yunsheng Qiao ◽  
Yuhong Chen ◽  
Chen Tan ◽  
Xinghuai Sun ◽  
Xueli Chen ◽  
...  

Purposes: Recent studies have suggested that loss-of-function mutations of the tunica intima endothelial receptor tyrosine kinase (TEK) are responsible for approximately 5% of primary congenital glaucoma (PCG) cases in diverse populations. However, the causative role of TEK mutations has not been studied in Chinese PCG patients. Here, we report the mutation spectrum of TEK after screening a large cohort of PCG patients of Chinese Han origin and analyze the identified variants in functional assays.Methods: TEK-targeted next-generation sequencing (NGS) was performed in 200 PCG patients. Candidate variants were prioritized by mutation type and allele frequency in public datasets. Plasmids containing wild type and identified variants of TEK were constructed and used to assess protein expression, solubility, receptor auto-phosphorylation, and response to ligand stimulation in cell-based assays.Results: Ten missense and one nonsense heterozygous variants were detected by NGS in 11 families. The clinical features of TEK variants carriers were comparable to that of TEK-mutated patients identified in other populations and CYP1B1-mutated individuals from in-house database. Functional analysis confirmed four variants involving evolutionarily conserved residues to be loss-of-function, while one variant (p.R1003H) located in tyrosine kinase domain seemed to be an activating mutation. However, our results did not support the pathogenicity of the other five variants (p.H52R, p.M131I, p.M228V, p.H494Y, and p.L888P).Conclusion: We provide evidence for TEK variants to be causative in Chinese PCG patients for the first time. Attention needs to be paid to TEK mutations in future genetic testing.

Diabetes ◽  
1992 ◽  
Vol 41 (4) ◽  
pp. 521-526 ◽  
Author(s):  
S. Cocozza ◽  
A. Porcellini ◽  
G. Riccardi ◽  
A. Monticelli ◽  
G. Condorelli ◽  
...  

Plants ◽  
2020 ◽  
Vol 9 (5) ◽  
pp. 664
Author(s):  
Allimuthu Elangovan ◽  
Monika Dalal ◽  
Gopinathan Kumar Krishna ◽  
Sellathdurai Devika ◽  
Ranjeet Ranjan Kumar ◽  
...  

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.


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

1995 ◽  
Vol 10 (3) ◽  
pp. 357-359 ◽  
Author(s):  
Gary A. Bellus ◽  
Iain McIntosh ◽  
E. Anne Smith ◽  
Arthur S. Aylsworth ◽  
Ilkka Kaitila ◽  
...  

2017 ◽  
Vol 34 (7) ◽  
Author(s):  
Matthew K. Stein ◽  
Lindsay Morris ◽  
Jennifer L. Sullivan ◽  
Moon Fenton ◽  
Ari VanderWalde ◽  
...  

2009 ◽  
Vol 29 (12) ◽  
pp. 3367-3378 ◽  
Author(s):  
Scott A. Robertson ◽  
Rositsa I. Koleva ◽  
Lawrence S. Argetsinger ◽  
Christin Carter-Su ◽  
Jarrod A. Marto ◽  
...  

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.


1994 ◽  
Vol 14 (9) ◽  
pp. 5812-5819
Author(s):  
H Shibuya ◽  
K Kohu ◽  
K Yamada ◽  
E L Barsoumian ◽  
R M Perlmutter ◽  
...  

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.


1993 ◽  
Vol 13 (1) ◽  
pp. 358-366
Author(s):  
I Bongarzone ◽  
N Monzini ◽  
M G Borrello ◽  
C Carcano ◽  
G Ferraresi ◽  
...  

The ret oncogene frequently has been found activated in papillary thyroid carcinomas. A previous characterization of ret activation revealed recombination of its tyrosine kinase domain and sequences derived from an uncharacterized locus (D10S170). The mechanism leading to this recombination was identified as a paracentric inversion of the long arm of chromosome 10, inv(10)(q11.2q21), with the breakpoints occurring where ret and D10S170 were mapped. To further characterize the activation of ret in papillary thyroid carcinomas, we have now isolated and sequenced a second type of ret oncogenic rearrangement not involving the D10S170 locus. The nucleotide sequence indicated that the transforming activity was created by the fusion of the ret tyrosine kinase domain with part of the RI alpha regulatory subunit of protein kinase A (PKA). This is the first example of an oncogenic activity involving a PKA gene. PKA is the main intracellular cyclic AMP receptor, and its RI alpha subunit gene is located on chromosome 17q. RI alpha-ret transcripts encode two isoforms of the chimeric protein (p76 and p81), which display constitutive tyrosine phosphorylation as well as a tyrosine kinase enzymatic activity. Under nonreducing conditions, both isoforms are found in a dimeric configuration because of both homo- and heterodimer formation. Thus, the in vivo activation of ret in human papillary thyroid carcinomas is provided by the fusion of its tyrosine kinase domain with different genes and can be mediated by different mechanisms of gene rearrangement.


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