scholarly journals Transcriptional regulation by methyltransferases and their role in the heart: highlighting novel emerging functionality

2020 ◽  
Vol 319 (4) ◽  
pp. H847-H865
Author(s):  
Marta W. Szulik ◽  
Kathryn Davis ◽  
Anna Bakhtina ◽  
Presley Azarcon ◽  
Ryan Bia ◽  
...  
Keyword(s):  
Heart Disease ◽  
Data Sets ◽  
Dual Roles ◽  
Human Heart Failure ◽  
Specific Expression ◽  
Histone Methyltransferases ◽  
Functional Studies ◽  
Tissue Profiling ◽  
Family Protein ◽  
Protein Methyltransferases

Methyltransferases are a superfamily of enzymes that transfer methyl groups to proteins, nucleic acids, and small molecules. Traditionally, these enzymes have been shown to carry out a specific modification (mono-, di-, or trimethylation) on a single, or limited number of, amino acid(s). The largest subgroup of this family, protein methyltransferases, target arginine and lysine side chains of histone molecules to regulate gene expression. Although there is a large number of functional studies that have been performed on individual methyltransferases describing their methylation targets and effects on biological processes, no analyses exist describing the spatial distribution across tissues or their differential expression in the diseased heart. For this review, we performed tissue profiling in protein databases of 199 confirmed or putative methyltransferases to demonstrate the unique tissue-specific expression of these individual proteins. In addition, we examined transcript data sets from human heart failure patients and murine models of heart disease to identify 40 methyltransferases in humans and 15 in mice, which are differentially regulated in the heart, although many have never been functionally interrogated. Lastly, we focused our analysis on the largest subgroup, that of protein methyltransferases, and present a newly emerging phenomenon in which 16 of these enzymes have been shown to play dual roles in regulating transcription by maintaining the ability to both activate and repress transcription through methyltransferase-dependent or -independent mechanisms. Overall, this review highlights a novel paradigm shift in our understanding of the function of histone methyltransferases and correlates their expression in heart disease.

Abstract 269: Miofibroblast Tgf-beta Signaling in a Proteotoxic Mouse Model

2016 ◽  
Vol 119 (suppl_1) ◽  
Author(s):  
Bidur Bhandary ◽  
Qinghang Meng ◽  
Hanna Osinska ◽  
Kritton Shay-Winkler ◽  
James Gulick ◽  
...  
Keyword(s):  
Heart Disease ◽  
Mouse Model ◽  
Cardiac Function ◽  
Transforming Growth Factor Beta ◽  
Cardiac Fibrosis ◽  
Transforming Growth Factor ◽  
Prolonged Survival ◽  
Tgfβ Signaling ◽  
Specific Expression ◽  
Western Blots

Introduction: Transforming Growth Factor Beta (TGFβ) is an important cytokine in mediating the fibrogenic response and, in particular, cardiac fibrosis. Extensive fibrosis accompanies the cardiac remodeling that occurs during development of the protein conformation-based disease caused by cardiomyocyte-specific expression of a mutant, small, heat shock-like protein and chaperone, aB crystallin (CryABR120G). During the onset of fibrosis, fibroblasts are activated to the so-called “myofibroblast” state and TGFβ binding is thought to mediate an essential signaling pathway underlying this process. Our central hypothesis is that TGFβ signaling processes that result in significant cardiac fibrosis in a mouse model of proteotoxic heart disease are mediated by cardiac fibroblasts, rather than cardiomyocytes. Here, we have partially ablated TGFβ signaling only in cardiac myofibroblasts to observe if cardiac fibrosis is reduced. Aims and Methods: The objective of this study was to understand the contributions of fibroblast-derived TGFβ signaling to the development of cardiac fibrosis in a proteotoxic mouse model that results in significant cardiac fibrosis. To test the hypothesis we partially deleted the myofibroblast specific canonical and non-canonical signaling by crossing CryAB R120G mice with Tgfbr1 or Tgfbr2 floxed mice. The double transgene containing mice were further crossed with activated myofibroblast specific Cre mice in which Cre expression was driven off the periostin promoter. Echocardiography, Masson’s Trichome staining, PCR arrays, IHC and western blots were performed to characterize the fibrotic progression in CryAB R120G transgenic mice. Results: We observed that myofibroblast-targeted partial knockdown of Tgf βr1 signaling prolonged survival, modestly reducing fibrosis and improving cardiac function . Similarly, Tgf βr2 partial knockdown prolonged survival, modestly reducing fibrosis without improving cardiac function during fibrosis development in CryAB R120G mice. Conclusion: These findings suggest that, in a model of proteotoxic heart disease, myofibroblast based TGFβ signaling in the heart may contribute to cardiac hypertrophy/dysfunction but cannot account entirely for the fibrotic response.

Stable transfer and restricted expression of a cloned class I gene encoding a secreted transplantation-like antigen

1985 ◽  
Vol 5 (6) ◽  
pp. 1295-1300
Author(s):  
Y Barra ◽  
K Tanaka ◽  
K J Isselbacher ◽  
G Khoury ◽  
G Jay
Keyword(s):  
Molecular Mechanisms ◽  
Cell Types ◽  
Class I ◽  
Regulatory Sequences ◽  
Transcriptional Enhancer ◽  
Gene Encoding ◽  
Specific Expression ◽  
Tissue Specific ◽  
Functional Studies ◽  
I Gene

The identification of a unique major histocompatibility complex class I gene, designated Q10, which encodes a secreted rather than a cell surface antigen has led to questions regarding its potential role in regulating immunological functions. Since the Q10 gene is specifically activated only in the liver, we sought to define the molecular mechanisms which control its expression in a tissue-specific fashion. Results obtained by transfection of the cloned Q10 gene, either in the absence or presence of a heterologous transcriptional enhancer, into a variety of cell types of different tissue derivations are consistent with the Q10 gene being regulated at two levels. The first is by a cis-dependent mechanism which appears to involve site-specific DNA methylation. The second is by a trans-acting mechanism which would include the possibility of an enhancer binding factor. The ability to efficiently express the Q10 gene in certain transfected cell lines offers an opportunity to obtain this secreted class I antigen in quantities sufficient for functional studies; this should also make it possible to define regulatory sequences which may be responsible for the tissue-specific expression of Q10.

Abstract 260: Autophagy And Necrosis Underlie Polyglutamine Amyloid Oligomer Induced Heart Failure.

Circulation ◽  
2007 ◽  
Vol 116 (suppl_16) ◽  
Author(s):  
Scott Pattison ◽  
Atsushi Sanbe ◽  
Raisa Klevitsky ◽  
Hanna Osinska ◽  
Jeffrey Robbins
Keyword(s):  
Heart Failure ◽  
Neurodegenerative Diseases ◽  
Pathogenic Mechanism ◽  
Positive Staining ◽  
Neural Cells ◽  
Conformational Structure ◽  
Human Heart Failure ◽  
Specific Expression ◽  
Amyloid Oligomers ◽  
Amyloid Oligomer

Introduction: Amyloid oligomers, the entities believed to cause toxicity in many neurodegenerative diseases, have been observed in mouse and human heart failure samples. Amyloid oligomers are a diverse group of proteins that differ in sequence, but share a common conformational structure, and may impart a shared pathogenic mechanism. The purpose of this study was to test the hypothesis that expression and accumulation of amyloid oligomers are cytotoxic and sufficient to directly cause heart failure. Polyglutamine (PQ) repeats (>50) are known to form amyloid oligomers and induce toxicity in neural cells, causing Huntington′s and other neurodegenerative diseases, while shorter PQ peptides are benign. Hypothesis: Cardiomyocyte-autonomous expression of an exogenous PQ amyloid oligomer will be toxic to cardiomyocytes and result in heart failure. Methods: Transgenic mice were created with cardiomyocyte-specific expression of an amyloid oligomer forming peptide of 83 PQ repeats (PQ83) or a non-amyloid forming peptide of 19 PQ repeats (PQ19) as a non-pathological control. Both constructs were HA tagged. Results: A PQ83 line with relatively low levels of expression was generated, along with a PQ19 line that expressed at approximately 9-fold the levels observed in the PQ83 line. Hearts expressing PQ83 develop cardiac dysfunction and dilation by 5 months and exhibit 100% mortality by 8 months of age, whereas PQ19 mice have normal cardiac function, morphology and lifespan. PQ83 protein accumulates in cardiomyocytes as SDS-insoluble aggresomes with amyloid oligomer-positive staining. PQ83 hearts exhibited no signs of apoptosis. Ultrastructural analysis revealed that PQ83 hearts undergo autophagy, as evidenced by increased autophagosomal and lysosomal content. PQ83 hearts also show characteristics of necrotic death, including infiltration of inflammatory cells, cardiomyocyte vacuolization and increased staining for the membrane attack complex that causes sarcolemmal permeabilization. The data confirm the hypothesis that expression of an exogenous amyloid oligomer is toxic to cardiomyocytes and is sufficient to cause heart failure. The pathogenic mechanism appears to lead to cardiomyocyte death through autophagy and necrosis.

scholarly journals Predicting cell-cycle expressed genes identifies canonical and non-canonical regulators of time-specific expression in Saccharomyces cerevisiae

2018 ◽  
Author(s):  
Nicholas L Panchy ◽  
John P. Lloyd ◽  
Shin-Han Shiu
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Cell Cycle ◽  
Target Genes ◽  
Specific Cell ◽  
Data Sets ◽  
Cell Cycle Regulators ◽  
Specific Expression ◽  
Regulatory Data ◽  
Time Specific ◽  
Cycle Regulation

AbstractThe collection all TFs, target genes and their interactions in an organism form a gene regulatory network (GRN), which underly complex patterns of transcription even in unicellular species. However, identifying which interactions regulate expression in a specific temporal context remains a challenging task. With multiple experimental and computational approaches to characterize GRNs, we predicted general and phase-specific cell-cycle expression in Saccharomyces cerevisiae using four regulatory data sets: chromatin immunoprecipitation (ChIP), TF deletion data (Deletion), protein binding microarrays (PBMs), and position weight matrices (PWMs). Our results indicate that the source of regulatory interaction information significantly impacts our ability to predict cell-cycle expression where the best model was constructed by combining selected TF features from ChIP and Deletion data as well as TF-TF interaction features in the form of feed-forward loops. The TFs that were the best predictors of cell-cycle expression were enriched for known cell-cycle regulators but also include regulators not implicated in cell-cycle regulation previously. In addition, ChIP and Deletion datasets led to the identification different subsets of TFs important for predicting cell-cycle expression. Finally, analysis of important TF-TF interaction features suggests that the GRN regulating cell cycle expression is highly interconnected and clustered around four groups of genes, two of which represent known cell-cycle regulatory complexes, while the other two contain TFs that are not known cell-cycle regulators (Ste12-Tex1 and Rap1-Hap1-Msn4), but are nonetheless important to regulating the timing of expression. Thus, not only do our models accurately reflect what is known about the regulation of the S. cerevisiae cell cycle, they can be used to discover regulatory factors which play a role in controlling expression during the cell cycle as well as other contexts with discrete temporal patterns of expression.

scholarly journals Analysis of exome-sequenced UK Biobank subjects implicates genes affecting risk of hyperlipidaemia

2020 ◽  
Author(s):  
David Curtis
Keyword(s):  
Rare Variants ◽  
Sequence Data ◽  
Lipid Lowering ◽  
P Value ◽  
Data Sets ◽  
Uk Biobank ◽  
Functional Studies ◽  
Exome Sequence Data ◽  
Rare Genetic Variants ◽  
The Uk

Rare genetic variants in LDLR, APOB and PCSK9 are known causes of familial hypercholesterolaemia and it is expected that rare variants in other genes will also have effects on hyperlipidaemia risk although such genes remain to be identified. The UK Biobank consists of a sample of 500,000 volunteers and exome sequence data is available for 50,000 of them. 11,490 of these were classified as hyperlipidaemia cases on the basis of having a relevant diagnosis recorded and/or taking lipid-lowering medication while the remaining 38,463 were treated as controls. Variants in each gene were assigned weights according to rarity and predicted impact and overall weighted burden scores were compared between cases and controls, including population principal components as covariates. One biologically plausible gene, HUWE1, produced statistically significant evidence for association after correction for testing 22,028 genes with a signed log10 p value (SLP) of -6.15, suggesting a protective effect of variants in this gene. Other genes with uncorrected p<0.001 are arguably also of interest, including LDLR (SLP=3.67), RBP2 (SLP=3.14), NPFFR1 (SLP=3.02) and ACOT9 (SLP=-3.19). Gene set analysis indicated that rare variants in genes involved in metabolism and energy can influence hyperlipidaemia risk. Overall, the results provide some leads which might be followed up with functional studies and which could be tested in additional data sets as these become available. This research has been conducted using the UK Biobank Resource.

scholarly journals Origins and Immunity Networking Functions of EDS1 Family Proteins

2020 ◽  
Vol 58 (1) ◽  
pp. 253-276 ◽  
Author(s):  
Dmitry Lapin ◽  
Deepak D. Bhandari ◽  
Jane E. Parker
Keyword(s):  
Coiled Coil ◽  
Seed Plants ◽  
Seed Plant ◽  
Functional Studies ◽  
Host Cell Death ◽  
Essential Surfaces ◽  
Family Protein ◽  
Protein Functions ◽  
Biotrophic Pathogens ◽  
Basal Immunity

The EDS1 family of structurally unique lipase-like proteins EDS1, SAG101, and PAD4 evolved in seed plants, on top of existing phytohormone and nucleotide-binding–leucine-rich-repeat (NLR) networks, to regulate immunity pathways against host-adapted biotrophic pathogens. Exclusive heterodimers between EDS1 and SAG101 or PAD4 create essential surfaces for resistance signaling. Phylogenomic information, together with functional studies in Arabidopsis and tobacco, identify a coevolved module between the EDS1–SAG101 heterodimer and coiled-coil (CC) HET-S and LOP-B (CCHELO) domain helper NLRs that is recruited by intracellular Toll-interleukin1-receptor (TIR) domain NLR receptors to confer host cell death and pathogen immunity. EDS1–PAD4 heterodimers have a different and broader activity in basal immunity that transcriptionally reinforces local and systemic defenses triggered by various NLRs. Here, we consider EDS1 family protein functions across seed plant lineages in the context of networking with receptor and helper NLRs and downstream resistance machineries. The different modes of action and pathway connectivities of EDS1 family members go some way to explaining their central role in biotic stress resilience.

scholarly journals Stable transfer and restricted expression of a cloned class I gene encoding a secreted transplantation-like antigen.

1985 ◽  
Vol 5 (6) ◽  
pp. 1295-1300 ◽  
Author(s):  
Y Barra ◽  
K Tanaka ◽  
K J Isselbacher ◽  
G Khoury ◽  
G Jay
Keyword(s):  
Molecular Mechanisms ◽  
Cell Types ◽  
Class I ◽  
Regulatory Sequences ◽  
Transcriptional Enhancer ◽  
Gene Encoding ◽  
Specific Expression ◽  
Tissue Specific ◽  
Functional Studies ◽  
I Gene

The identification of a unique major histocompatibility complex class I gene, designated Q10, which encodes a secreted rather than a cell surface antigen has led to questions regarding its potential role in regulating immunological functions. Since the Q10 gene is specifically activated only in the liver, we sought to define the molecular mechanisms which control its expression in a tissue-specific fashion. Results obtained by transfection of the cloned Q10 gene, either in the absence or presence of a heterologous transcriptional enhancer, into a variety of cell types of different tissue derivations are consistent with the Q10 gene being regulated at two levels. The first is by a cis-dependent mechanism which appears to involve site-specific DNA methylation. The second is by a trans-acting mechanism which would include the possibility of an enhancer binding factor. The ability to efficiently express the Q10 gene in certain transfected cell lines offers an opportunity to obtain this secreted class I antigen in quantities sufficient for functional studies; this should also make it possible to define regulatory sequences which may be responsible for the tissue-specific expression of Q10.

scholarly journals Molecular basis of resistance to organophosphate insecticides in the New World screw-worm fly

2020 ◽  
Vol 13 (1) ◽  
Author(s):  
Sophie Tandonnet ◽  
Gisele Antoniazzi Cardoso ◽  
Pedro Mariano-Martins ◽  
Raquel Dietsche Monfardini ◽  
Vanessa A. S. Cunha ◽  
...  
Keyword(s):  
Insecticide Resistance ◽  
Molecular Basis ◽  
Pyrethroid Resistance ◽  
Management Strategies ◽  
Evolutionary Process ◽  
Specific Expression ◽  
Altered Expression ◽  
Functional Studies ◽  
Expression Of Genes ◽  
Starting Point

Abstract Background The emergence of insecticide resistance is a fast-paced example of the evolutionary process of natural selection. In this study, we investigated the molecular basis of resistance in the myiasis-causing fly Cochliomyia hominivorax (Diptera: Calliphoridae) to dimethyl-organophosphate (OP) insecticides. Methods By sequencing the RNA from surviving larvae treated with dimethyl-OP (resistant condition) and non-treated larvae (control condition), we identified genes displaying condition-specific polymorphisms, as well as those differentially expressed. Results Both analyses revealed that resistant individuals have altered expression and allele-specific expression of genes involved in proteolysis (specifically serine-endopeptidase), olfactory perception and cuticle metabolism, among others. We also confirmed that resistant individuals carry almost invariably the Trp251Ser mutation in the esterase E3, known to confer OP and Pyrethroid resistance. Interestingly, genes involved in metabolic and detoxifying processes (notably cytochrome P450s) were found under-expressed in resistant individuals. An exception to this were esterases, which were found up-regulated. Conclusions These observations suggest that reduced penetration and aversion to dimethyl-OP contaminated food may be important complementary strategies of resistant individuals. The specific genes and processes found are an important starting point for future functional studies. Their role in insecticide resistance merits consideration to better the current pest management strategies.

scholarly journals MroQ Is a Novel Abi-Domain Protein That Influences Virulence Gene Expression in Staphylococcus aureus via Modulation of Agr Activity

2019 ◽  
Vol 87 (5) ◽  
Author(s):  
Stephanie Marroquin ◽  
Brittney Gimza ◽  
Brooke Tomlinson ◽  
Michelle Stein ◽  
Andrew Frey ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Virulence Gene ◽  
Transcriptional Analysis ◽  
Data Sets ◽  
Virulence Determinants ◽  
Sequencing Data ◽  
Content Type ◽  
Virulence Gene Expression ◽  
Function Mechanism ◽  
Family Protein

ABSTRACT Numerous factors have, to date, been identified as playing a role in the regulation of Agr activity in Staphylococcus aureus, including transcription factors, antisense RNAs, and host elements. Herein we investigated the product of SAUSA300_1984 (termed MroQ), a transmembrane Abi-domain/M79 protease-family protein, as a novel effector of this system. Using a USA300 mroQ mutant, we observed a drastic reduction in proteolysis, hemolysis, and pigmentation that was fully complementable. This appears to result from diminished agr activity, as transcriptional analysis revealed significant decreases in expression of both RNAII and RNAIII in the mroQ mutant. Such effects appear to be direct, rather than indirect, as known agr effectors demonstrated limited alterations in their activity upon mroQ disruption. A comparison of RNA sequencing data sets for both mroQ and agr mutants revealed a profound overlap in their regulomes, with the majority of factors affected being known virulence determinants. Importantly, the preponderance of alterations in expression were more striking in the agr mutant, indicating that MroQ is necessary, but not sufficient, for Agr function. Mechanism profiling revealed that putative residues for metalloprotease activity within MroQ are required for its Agr-controlling effect; however, this was not wielded at the level of AgrD processing. Virulence assessment demonstrated that both mroQ and agr mutants exhibited increased formation of renal abscesses but decreased skin abscess formation alongside diminished dermonecrosis. Collectively, we present the characterization of a novel agr effector in S. aureus which would appear to be a direct regulator, potentially functioning via interaction with the AgrC histidine kinase.

scholarly journals Repeated Evolution of Testis-Specific New Genes: The Case of Telomere-Capping Genes in Drosophila

2012 ◽  
Vol 2012 ◽  
pp. 1-11 ◽  
Author(s):  
Raphaëlle Dubruille ◽  
Gabriel A. B. Marais ◽  
Benjamin Loppin
Keyword(s):  
Gene Family ◽  
Specific Expression ◽  
Functional Studies ◽  
Evolutionary Forces ◽  
New Genes ◽  
Male Gametes ◽  
Duplication Events ◽  
New Gene ◽  
Telomere Capping ◽  
Specific Expression Pattern

Comparative genome analysis has allowed the identification of various mechanisms involved in gene birth. However, understanding the evolutionary forces driving new gene origination still represents a major challenge. In particular, an intriguing and not yet fully understood trend has emerged from the study of new genes: many of them show a testis-specific expression pattern, which has remained poorly understood. Here we review the case of such a new gene, which involves a telomere-capping gene family in Drosophila. hiphop and its testis-specific paralog K81 are critical for the protection of chromosome ends in somatic cells and male gametes, respectively. Two independent functional studies recently proposed that these genes evolved under a reproductive-subfunctionalization regime. The 2011 release of new Drosophila genome sequences from the melanogaster group of species allowed us to deepen our phylogenetic analysis of the hiphop/K81 family. This work reveals an unsuspected dynamic of gene birth and death within the group, with recurrent duplication events through retroposition mechanisms. Finally, we discuss the plausibility of different evolutionary scenarios that could explain the diversification of this gene family.

Sign in / Sign up

Export Citation Format

Share Document