scholarly journals Identification and characterization of novel ACD variants: modulation of TPP1 protein level offsets the impact of germline loss-of-function variants on telomere length

2021 ◽  
Vol 7 (1) ◽  
pp. a005454
Author(s):  
Gabrielle Henslee ◽  
Christopher L. Williams ◽  
Pengfei Liu ◽  
Alison A. Bertuch
Keyword(s):  
Telomere Length ◽  
Protein Level ◽  
Loss Of Function ◽  
The Impact ◽  
Identification And Characterization

scholarly journals The Okur-Chung Neurodevelopmental Syndrome (OCNDS) mutation CK2K198R leads to a rewiring of kinase specificity

2021 ◽  
Author(s):  
Danielle M Caefer ◽  
Nhat Q Phan ◽  
Jennifer C Liddle ◽  
Jeremy L Balsbaugh ◽  
Joseph P O’Shea ◽  
...  
Keyword(s):  
High Resolution ◽  
Substrate Specificity ◽  
Tyrosine Phosphorylation ◽  
Initial Step ◽  
Loss Of Function ◽  
Scoring Method ◽  
Disease Condition ◽  
The Impact ◽  
First Time

AbstractOkur-Chung Neurodevelopmental Syndrome (OCNDS) is caused by heterozygous mutations to the CSNK2A1 gene, which encodes the alpha subunit of casein kinase II (CK2). The most frequently occurring mutation is lysine 198 to arginine (K198R). To investigate the impact of this mutation, we first generated a high-resolution phosphorylation motif of CK2WT, including the first characterization of specificity for tyrosine phosphorylation activity. A second high resolution motif representing CK2K198R substrate specificity was also generated. Here we report for the first time the impact of the OCNDS associated CK2K198R mutation. Contrary to prior speculation, the mutation does not result in a loss of function, but rather shifts the substrate specificity of the kinase. Broadly speaking the mutation leads to 1) a decreased preference for acidic residues in the +1 position, 2) a decreased preference for threonine phosphorylation, 3) an increased preference for tyrosine phosphorylation, and 4) an alteration of the tyrosine phosphorylation specificity motif. To further investigate the result of this mutation we have developed a probability-based scoring method, allowing us to predict shifts in phosphorylation in the K198R mutant relative to the wild type kinase. As an initial step we have applied the methodology to the set of axonally localized ion channels in an effort to uncover potential alterations of the phosphoproteome associated with the OCNDS disease condition.

scholarly journals Human xylosyltransferase I and N-terminal truncated forms: functional characterization of the core enzyme

2006 ◽  
Vol 394 (1) ◽  
pp. 163-171 ◽  
Author(s):  
Sandra Müller ◽  
Jennifer Disse ◽  
Manuela Schöttler ◽  
Sylvia Schön ◽  
Christian Prante ◽  
...  
Keyword(s):  
Amino Acids ◽  
Catalytic Activity ◽  
Binding Capacity ◽  
Functional Characterization ◽  
Terminal Region ◽  
Binding Motif ◽  
Heparin Binding ◽  
Loss Of Function ◽  
The Impact

Human XT-I (xylosyltransferase I; EC 2.4.2.26) initiates the biosynthesis of the glycosaminoglycan linkage region and is a diagnostic marker of an enhanced proteoglycan biosynthesis. In the present study, we have investigated mutant enzymes of human XT-I and assessed the impact of the N-terminal region on the enzymatic activity. Soluble mutant enzymes of human XT-I with deletions at the N-terminal domain were expressed in insect cells and analysed for catalytic activity. As many as 260 amino acids could be truncated at the N-terminal region of the enzyme without affecting its catalytic activity. However, truncation of 266, 272 and 273 amino acids resulted in a 70, 90 and >98% loss in catalytic activity. Interestingly, deletion of the single 12 amino acid motif G261KEAISALSRAK272 leads to a loss-of-function XT-I mutant. This is in agreement with our findings analysing the importance of the Cys residues where we have shown that C276A mutation resulted in a nearly inactive XT-I enzyme. Moreover, we investigated the location of the heparin-binding site of human XT-I using the truncated mutants. Heparin binding was observed to be slightly altered in mutants lacking 289 or 568 amino acids, but deletion of the potential heparin-binding motif P721KKVFKI727 did not lead to a loss of heparin binding capacity. The effect of heparin or UDP on the XT-I activity of all mutants was not significantly different from that of the wild-type. Our study demonstrates that over 80% of the nucleotide sequence of the XT-I-cDNA is necessary for expressing a recombinant enzyme with full catalytic activity.

scholarly journals Neuronal KGB-1 JNK MAPK signaling regulates the dauer developmental decision in response to environmental stress in C. elegans

2021 ◽  
Author(s):  
Deepshikha Dogra ◽  
Warakorn Kulalert ◽  
Frank Schroeder ◽  
Dennis H Kim
Keyword(s):  
Elevated Temperature ◽  
Signaling Pathways ◽  
Mapk Pathway ◽  
Negative Regulator ◽  
Loss Of Function ◽  
C Elegans ◽  
Metabolic Remodeling ◽  
Dauer Formation ◽  
Identification And Characterization

In response to stressful growth conditions of high population density, food scarcity and elevated temperature, young larvae of nematode Caenorhabditis elegans can enter a developmentally arrested stage called dauer that is characterized by dramatic anatomic and metabolic remodeling. Genetic analysis of dauer formation of C. elegans has served as an experimental paradigm for the identification and characterization of conserved neuroendocrine signaling pathways. Here, we report the identification and characterization of a conserved JNK-like mitogen-activated protein kinase (MAPK) pathway that is required for dauer formation in response to environmental stressors. We observed that loss-of-function mutations in the MLK-1-MEK-1-KGB-1 MAPK pathway suppress dauer entry. Loss-of-function mutation in the VHP-1 MAPK phosphatase, a known negative regulator of KGB-1 signaling, results in constitutive dauer formation which is dependent on the presence of dauer pheromone but independent of diminished food levels or elevated temperatures. Our data suggest that KGB-1 pathway acts in the sensory neurons, in parallel to established insulin and TGF-β signaling pathways, to transduce the dauer-inducing environmental cues of diminished food levels and elevated temperature.

scholarly journals Super Secondary Structures of Proteins with Post-Translational Modifications in Colon Cancer

Molecules ◽  
2020 ◽  
Vol 25 (14) ◽  
pp. 3144
Author(s):  
Dmitry Tikhonov ◽  
Liudmila Kulikova ◽  
Arthur Kopylov ◽  
Kristina Malsagova ◽  
Alexander Stepanov ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Control Cell ◽  
Three Dimensional ◽  
Vitamin D Binding Protein ◽  
High Throughput Analysis ◽  
Post Translational Modifications ◽  
New Strategy ◽  
The Impact ◽  
Identification And Characterization

New advances in protein post-translational modifications (PTMs) have revealed a complex layer of regulatory mechanisms through which PTMs control cell signaling and metabolic pathways, contributing to the diverse metabolic phenotypes found in cancer. Using conformational templates and the three-dimensional (3D) environment investigation of proteins in patients with colorectal cancer, it was demonstrated that most PTMs (phosphorylation, acetylation, and ubiquitination) are localized in the supersecondary structures (helical pairs). We showed that such helical pairs are represented on the outer surface of protein molecules and characterized by a largely accessible area for the surrounding solvent. Most promising and meaningful modifications were observed on the surface of vitamin D-binding protein (VDBP), complement C4-A (CO4A), X-ray repair cross-complementing protein 6 (XRCC6), Plasma protease C1 inhibitor (IC1), and albumin (ALBU), which are related to colorectal cancer developing. Based on the presented data, we propose the impact of the observed modifications in immune response, inflammatory reaction, regulation of cell migration, and promotion of tumor growth. Here, we suggest a computational approach in which high-throughput analysis for identification and characterization of PTM signature, associated with cancer metabolic reprograming, can be improved to prognostic value and bring a new strategy to the targeted therapy.

scholarly journals Analysis of the Environmental Impact of the Energy Retrofitting Carried Out in a Low-income Residential Neighbourhood. The Case of Juan XXIII in Alicante, Spain

2017 ◽  
Vol 11 (1) ◽  
pp. 65-82 ◽  
Author(s):  
Begoña Serrano-Lanzarote ◽  
Laura Soto Francés ◽  
Leticia Ortega Madrigal ◽  
Alejandra García-Prieto Ruiz
Keyword(s):  
Low Income ◽  
Dysfunctional Families ◽  
Energy Evaluation ◽  
Quality Life ◽  
Consumption Reduction ◽  
Improvement Measures ◽  
The Cost ◽  
The Impact ◽  
Identification And Characterization

This article presents the analysis of the improvement measures applied on an energy retrofitting carried out to 324 dwellings built in 1967 at Juan XXIII neighbourhood in Alicante (Spain). The impact on consumption reduction and the cost of each measure are shown. The neighbourhood presents significant levels of urban obsolescence, partly motivated by the poor constructive quality caused by the intense rhythm followed during its construction. Furthermore, at that time, Spain lacked specific regulations on energy saving issues. The latter is the reason why the buildings have an evident inefficient behaviour. In addition to all this, there is a significant social and economic vulnerability in the neighbourhood, with dysfunctional families and high unemployment levels. All of the stages of the retrofitting process are presented, starting from the identification and characterization of constructive elements in their original state to the analysis of the improvement measures and the energy evaluation and used tools. Finally, these are demonstrated as the improvements in energy efficiency can produce a better quality life for the inhabitants, constituting a powerful strategy to dignify a neighbourhood, from environmental, social and economic aspects.

Non-O157 Verotoxin-Producing Escherichia coli: A Problem, Paradox, and Paradigm

2003 ◽  
Vol 228 (4) ◽  
pp. 333-344 ◽  
Author(s):  
Karl A. Bettelheim
Keyword(s):  
Escherichia Coli ◽  
Animal Health ◽  
Domestic Animals ◽  
Emerging Pathogens ◽  
E Coli ◽  
The Impact ◽  
Identification And Characterization

The problems associated with identification and characterization of non-O157 verotoxin-producing Escherichia coli (VTEC) are discussed. The paradox of VTEC is that most reports of human illnesses are associated with serotypes such as O157:H7, O111:H– (nonmotile), O26:H11, and O113:H21, which are rarely found in domestic animals. However, those VTEC serotypes commonly found in domestic animals, especially ruminants, rarely cause human illnesses. When they cause human illnesses, the symptoms are similar to those caused by the serotypes E. coli O157:H7, O111:H–, O26:H11, and O113:H21. The impact of VTEC on human and animal health is also addressed. The VTEC and their toxicity are considered as a paradigm for emerging pathogens. The question on how such pathogens could arise from a basic commensal population is also addressed.

scholarly journals Biological and Regulatory Properties of Vav-3, a New Member of the Vav Family of Oncoproteins

1999 ◽  
Vol 19 (11) ◽  
pp. 7870-7885 ◽  
Author(s):  
Nieves Movilla ◽  
Xosé R. Bustelo
Keyword(s):  
Tyrosine Kinases ◽  
Protein Tyrosine Kinases ◽  
Nucleotide Exchange ◽  
Loss Of Function ◽  
Wild Type ◽  
Gtp Binding ◽  
Regulatory Properties ◽  
Identification And Characterization

ABSTRACT We report here the identification and characterization of a novel Vav family member, Vav-3. Signaling experiments demonstrate that Vav-3 participates in pathways activated by protein tyrosine kinases. Vav-3 promotes the exchange of nucleotides on RhoA, on RhoG and, to a lesser extent, on Rac-1. During this reaction, Vav-3 binds physically to the nucleotide-free states of those GTPases. These functions are stimulated by tyrosine phosphorylation in wild-type Vav-3 and become constitutively activated upon deletion of the entire calponin-homology region. Expression of truncated versions of Vav-3 leads to drastic actin relocalization and to the induction of stress fibers, lamellipodia, and membrane ruffles. Moreover, expression of Vav-3 alters cytokinesis, resulting in the formation of binucleated cells. All of these responses need only the expression of the central region of Vav-3 encompassing the Dbl homology (DH), pleckstrin homology (PH), and zinc finger (ZF) domains but do not require the presence of the C-terminal SH3-SH2-SH3 regions. Studies conducted with Vav-3 proteins containing loss-of-function mutations in the DH, PH, and ZF regions indicate that only the DH and ZF regions are essential for Vav-3 biological activity. Finally, we show that one of the functions of the Vav-3 ZF region is to work coordinately with the catalytic DH region to promote both the binding to GTP-hydrolases and their GDP-GTP nucleotide exchange. These results highlight the role of Vav-3 in signaling and cytoskeletal pathways and identify a novel functional cross-talk between the DH and ZF domains of Vav proteins that is imperative for the binding to, and activation of, Rho GTP-binding proteins.

scholarly journals Defects in glucuronate biosynthesis disrupt Wingless signaling in Drosophila

Development ◽  
1997 ◽  
Vol 124 (16) ◽  
pp. 3055-3064 ◽  
Author(s):  
T.E. Haerry ◽  
T.R. Heslip ◽  
J.L. Marsh ◽  
M.B. O'Connor
Keyword(s):  
Glucuronic Acid ◽  
Germ Line ◽  
Glucose Dehydrogenase ◽  
Growth Factor Signaling ◽  
Loss Of Function ◽  
Core Proteins ◽  
Identification And Characterization

In vitro experiments suggest that glycosaminoglycans (GAGs) and the proteins to which they are attached (proteoglycans) are important for modulating growth factor signaling. However, in vivo evidence to support this view has been lacking, in part because mutations that disrupt the production of GAG polymers and the core proteins have not been available. Here we describe the identification and characterization of Drosophila mutants in the suppenkasper (ska) gene. The ska gene encodes UDP-glucose dehydrogenase which produces glucuronic acid, an essential component for the synthesis of heparan and chondroitin sulfate. ska mutants fail to put heparan side chains on proteoglycans such as Syndecan. Surprisingly, mutant embryos produced by germ-line clones of this general metabolic gene exhibit embryonic cuticle phenotypes strikingly similar to those that result from loss-of-function mutations in genes of the Wingless (Wg) signaling pathway. Zygotic loss of ska leads to reduced growth of imaginal discs and pattern defects similar to wg mutants. In addition, genetic interactions of ska with wg and dishevelled mutants are observed. These data demonstrate the importance of proteoglycans and GAGs in Wg signaling in vivo and suggest that Wnt-like growth factors may be particularly sensitive to perturbations of GAG biosynthesis.

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