Publications by authors named "Pelech S"

Compounds targeting host control of infectious diseases provide an attractive alternative to antimicrobials. A phenotypic screen of a kinase library identified compounds targeting glycogen synthase kinase 3 as potent inhibitors of (Mtb) intracellular growth in the human THP-1 cell line and primary human monocytes-derived macrophages (hMDM). CRISPR knockouts and siRNA silencing showed that GSK3 isoforms are needed for the growth of Mtb and that a selected compound, P-4423632 targets GSK3β.

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Phosphorylation plays a key role in Alzheimer's disease (AD) pathogenesis, impacting distinct processes such as amyloid-beta (Aβ) peptide production and tau phosphorylation. Impaired phosphorylation events contribute to senile plaques and neurofibrillary tangles' formation, two major histopathological hallmarks of AD. Blood-derived extracellular particles (bdEP) can represent a disease-related source of phosphobiomarker candidates, and hence, in this pilot study, bdEP of Control and AD cases were analyzed by a targeted phosphoproteomics approach using a high-density microarray that featured at least 1145 pan-specific and 913 phosphosite-specific antibodies.

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Fatty acids stored in triacylglycerol-rich lipid droplets are assembled with a surface monolayer composed primarily of phosphatidylcholine (PC). Fatty acids stimulate PC synthesis by translocating CTP:phosphocholine cytidylyltransferase (CCT) α to the inner nuclear membrane, nuclear lipid droplets (nLD) and lipid associated promyelocytic leukemia (PML) structures (LAPS). Huh7 cells were used to identify how CCTα translocation onto these nuclear structures are regulated by fatty acids and phosphorylation of its serine-rich P-domain.

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Antibody microarray data provides a powerful and high-throughput tool to monitor global changes in cellular response to perturbation or genetic manipulation. However, while collecting such data has become increasingly accessible, a lack of specific computational tools has made their analysis limited. Here we present CAT PETR, a user friendly web application for the differential analysis of expression and phosphorylation data collected via antibody microarrays.

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This work aimed to understand how lifelong exercise training promotes the remodelling of the immune system and prostate signalome in a rat model of PCa. Fifty-five male Wistar rats were divided into four groups: control sedentary, control exercised, induced PCa sedentary and induced PCa exercised. Exercised animals were trained in a treadmill for 53 weeks.

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GSK3β has been proposed to have an essential role in Coronaviridae infections. Screening of a targeted library of GSK3β inhibitors against both SARS-CoV-2 and HCoV-229E to identify broad-spectrum anti-Coronaviridae inhibitors resulted in the identification of a high proportion of active compounds with low toxicity to host cells. A selected lead compound, T-1686568, showed low micromolar, dose-dependent activity against SARS-CoV-2 and HCoV-229E.

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The non-receptor focal adhesion kinase (FAK) is highly expressed in the central nervous system during development, where it regulates neurite outgrowth and axon guidance, but its role in the adult healthy and diseased brain, specifically in Alzheimer's disease (AD), is largely unknown. Using the 3xTg-AD mouse model, which carries three mutations associated with familial Alzheimer's disease (APP KM670/671NL Swedish, PSEN1 M146V, MAPT P301L) and develops age-related progressive neuropathology including amyloid plaques and Tau tangles, we describe here, for the first time, the in vivo role of FAK in AD pathology. Our data demonstrate that while site-specific knockdown in the hippocampi of 3xTg-AD mice has no effect on learning and memory, hippocampal overexpression of the protein leads to a significant decrease in learning and memory capabilities, which is accompanied by a significant increase in amyloid β (Aβ) load.

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We have developed a method for the inexpensive, high-level expression of antigenic protein fragments of SARS-CoV-2 proteins in Escherichia coli. Our approach uses the thermophilic family 9 carbohydrate-binding module (CBM9) as an N-terminal carrier protein and affinity tag. The CBM9 module was joined to SARS-CoV-2 protein fragments via a flexible proline-threonine linker, which proved to be resistant to E.

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Heart disease is an integral part of Friedreich ataxia (FA) and the most common cause of death in this autosomal recessive disease. The result of the mutation is lack of frataxin, a small mitochondrial protein. The clinical and pathological phenotypes of FA are complex, involving brain, spinal cord, dorsal root ganglia, sensory nerves, heart, and endocrine pancreas.

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As part of the Reproducibility Project: Cancer Biology, we published Registered Reports that described how we intended to replicate selected experiments from 29 high-impact preclinical cancer biology papers published between 2010 and 2012. Replication experiments were completed and Replication Studies reporting the results were submitted for 18 papers, of which 17 were accepted and published by with the rejected paper posted as a preprint. Here, we report the status and outcomes obtained for the remaining 11 papers.

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Vaccines have been developed at "warp speed" to combat the COVID-19 pandemic caused by the SARS-CoV-2 coronavirus. Although they are considered the best approach for preventing mortality, when assessing the safety of these vaccines, pregnant women have not been included in clinical trials. Thus, vaccine safety for this demographic, as well as for the developing fetus and neonate, remains to be determined.

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Preexisting cross-reactivity to SARS-CoV-2 occurs in the absence of prior viral exposure. However, this has been difficult to quantify at the population level due to a lack of reliably defined seroreactivity thresholds. Using an orthogonal antibody testing approach, we estimated that about 0.

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Prostate cancer (PCa) treatment remains challenging, especially in advanced stages, where the lack of sensitivity and specificity of available biomarkers makes it difficult to establish an accurate prognosis. Therefore, it is imperative to study PCa biology to identify key molecules that can improve PCa management. In this study, eight prostate tumor tissues and paired normal tissues were analyzed using two approaches-Fourier-transform infrared (FT-IR) spectroscopy for spectroscopic profiling of biomolecules and antibody microarray for signaling proteins-with the main goal of identifying metabolic and proteomic changes that enable the distinction between normal and tumor conditions.

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CTP:phosphocholine cytidylyltransferase-alpha (CCTα) and CCTβ catalyze the rate-limiting step in phosphatidylcholine (PC) biosynthesis. CCTα is activated by association of its α-helical M-domain with nuclear membranes, which is negatively regulated by phosphorylation of the adjacent P-domain. To understand how phosphorylation regulates CCT activity, we developed phosphosite-specific antibodies for pS319 and pY359+pS362 at the N- and C-termini of the P-domain, respectively.

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Habituation is a ubiquitous form of non-associative learning observed as a decrement in responding to repeated stimulation that cannot be explained by sensory adaptation or motor fatigue. One of the defining characteristics of habituation is its sensitivity to the rate at which training stimuli are presented-animals habituate faster in response to more rapid stimulation. The molecular mechanisms underlying this interstimulus interval (ISI)-dependent characteristic of habituation remain unknown.

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Cyclin-dependent kinase 5 (CDK5) is a multifunctional serine/threonine kinase that regulates a large number of neuronal processes essential for nervous system development and function with its activator p35 CDK5R1. Upon neuronal insults, p35 is proteolyzed and cleaved to p25 producing deregulation and hyperactivation of CDK5 (CDK5/p25), implicated in tau hyperphosphorylation, a pathology in some neurodegenerative diseases. A truncated, 24 amino acid peptide, p5, derived from p35 inhibits the deregulated CDK5 phosphotransferase activity and ameliorates Alzheimer's disease (AD) phenotypes in AD model mice.

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The Reproducibility Project: Cancer Biology seeks to address growing concerns about reproducibility in scientific research by conducting replications of selected experiments from a number of high-profile papers in the field of cancer biology. The papers, which were published between 2010 and 2012, were selected on the basis of citations and Altmetric scores (Errington et al., 2014).

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The catalytic domains of most eukaryotic protein kinases are highly conserved in their primary structures. Their phosphorylation within the well-known activation T-loop, a variable region between protein kinase catalytic subdomains VII and VIII, is a common mechanism for stimulation of their phosphotransferase activities. Extracellular signal-regulated kinase 1 (ERK1), a member of the extensively studied mitogen-activated protein kinase (MAPK) family, serves as a paradigm for regulation of protein kinases in signaling modules.

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The reversible phosphorylation of proteins catalyzed by protein kinases in eukaryotes supports an important role for eukaryotic protein kinases (ePKs) in the emergence of nucleated cells in the third superkingdom of life. Choline kinases (ChKs) could also be critical in the early evolution of eukaryotes, because of their function in the biosynthesis of phosphatidylcholine, which is unique to eukaryotic membranes. However, the genomic origins of ePKs and ChKs are unclear.

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Elucidation of the key determinants for the phosphorylation site specificities of protein kinases facilitates identification of their physiological substrates, and serves to better define their critical roles in the signaling networks that underlie a multitude of cellular activities. Albeit with some apparent limitations, such as the lack of contextual information for secondary substrate-binding sites, the synthetic peptide-based approach has been adopted widely for the kinase specificity profiling studies, especially when they are used in an array format, which permits the screening of large numbers of potential peptide substrates in parallel. In this chapter, we present detailed protocols for determining protein kinase substrate specificity using an approach that involves both peptide microarrays and macroarrays.

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Fuelled by advances in our understanding of the human kinome and phosphoproteome and the increasing availability of pan- and phosphosite-specific antibodies, antibody microarrays have emerged as powerful tools for interrogating protein phosphorylation-mediated signaling systems in ex vivo studies. This economical platform permits ultra-sensitive, semiquantitative measurements of the levels of hundreds of protein kinases and their substrates along with their phosphorylation status simultaneously with minute amounts of specimens. Recent technological innovations in the design and fabrication of antibody microarrays and sample preparation have permitted further refinements of the technology to yield improvements in data quality.

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Besides the hallmark pathology of amyloid plaques and neurofibrillary tangles, it is well documented that cyclin-dependent kinase 5 (CDK5), a critical neuronal protein kinase in nervous system development, function, and survival, when deregulated and hyperactivated induces Alzheimer's disease (AD) and amyotrophic lateral sclerosis and Parkinson's disease-like phenotypes in mice. In a recent study, we demonstrated that p5, a small, truncated fragment of 24 amino acid residues derived from the CDK5 activator protein 35 (NCK5A, p35), selectively inhibited deregulated CDK5 hyperactivity and ameliorated AD phenotypes in model mice. In this study, we identified the most inhibitory elements in the p5 peptide fragment.

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Objective: To determine the correlation between semen basic parameters and the expression and activity of signaling proteins.

Design: In vitro studies with human spermatozoa.

Setting: Academic research institute.

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