scholarly journals Blood disease–causing and –suppressing transcriptional enhancers: general principles and GATA2 mechanisms

2019 ◽  
Vol 3 (13) ◽  
pp. 2045-2056 ◽  
Author(s):  
Emery H. Bresnick ◽  
Kirby D. Johnson
Keyword(s):  
Genetic Variation ◽  
Regulatory Sequence ◽  
Regulatory Sequences ◽  
Sequence Motifs ◽  
Cis Elements ◽  
Noncoding Regions ◽  
Transcriptional Enhancers ◽  
Blood Disease ◽  
New Genes ◽  
Functional Consequences

Abstract Intensive scrutiny of human genomes has unveiled considerable genetic variation in coding and noncoding regions. In cancers, including those of the hematopoietic system, genomic instability amplifies the complexity and functional consequences of variation. Although elucidating how variation impacts the protein-coding sequence is highly tractable, deciphering the functional consequences of variation in noncoding regions (genome reading), including potential transcriptional-regulatory sequences, remains challenging. A crux of this problem is the sheer abundance of gene-regulatory sequence motifs (cis elements) mediating protein-DNA interactions that are intermixed in the genome with thousands of look-alike sequences lacking the capacity to mediate functional interactions with proteins in vivo. Furthermore, transcriptional enhancers harbor clustered cis elements, and how altering a single cis element within a cluster impacts enhancer function is unpredictable. Strategies to discover functional enhancers have been innovated, and human genetics can provide vital clues to achieve this goal. Germline or acquired mutations in functionally critical (essential) enhancers, for example at the GATA2 locus encoding a master regulator of hematopoiesis, have been linked to human pathologies. Given the human interindividual genetic variation and complex genetic landscapes of hematologic malignancies, enhancer corruption, creation, and expropriation by new genes may not be exceedingly rare mechanisms underlying disease predisposition and etiology. Paradigms arising from dissecting essential enhancer mechanisms can guide genome-reading strategies to advance fundamental knowledge and precision medicine applications. In this review, we provide our perspective of general principles governing the function of blood disease–linked enhancers and GATA2-centric mechanisms.

scholarly journals Expanding the potential genes of inborn errors of immunity through protein interactions

BMC Genomics ◽  
2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Humza A. Khan ◽  
Manish J. Butte
Keyword(s):  
Genetic Variation ◽  
Protein Interactions ◽  
Immune Cell ◽  
Genetic Disorders ◽  
Cell Types ◽  
Protein Protein Interactions ◽  
Inborn Errors ◽  
Post Translational Modifications ◽  
New Genes ◽  
Inborn Errors Of Immunity

Abstract Background Inborn errors of immunity (IEI) are a group of genetic disorders that impair the immune system, with over 400 genes described so far, and hundreds more to be discovered. To facilitate the search for new genes, we need a way to prioritize among all the genes in the genome those most likely to play an important role in immunity. Results Here we identify a new list of genes by linking known IEI genes to new ones by using open-source databases of protein-protein interactions, post-translational modifications, and transcriptional regulation. We analyze this new set of 2,530 IEI-related genes for their tolerance of genetic variation and by their expression levels in various immune cell types. Conclusions By merging genes derived from protein interactions of known IEI genes with transcriptional data, we offer a new list of candidate genes that may play a role in as-yet undiscovered IEIs.

scholarly journals Identification and characterization of constrained non-exonic bases lacking predictive epigenomic and transcription factor binding annotations

2019 ◽  
Author(s):  
Olivera Grujic ◽  
Tanya N. Phung ◽  
Soo Bin Kwon ◽  
Adriana Arneson ◽  
Yuju Lee ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Transcription Factor Binding ◽  
Regulatory Sequence ◽  
Human Genetic Variation ◽  
Sequence Motifs ◽  
Variant Prioritization ◽  
Factor Binding ◽  
Genome Wide ◽  
Identification And Characterization

AbstractAnnotations of evolutionarily constraint provide important information for variant prioritization. Genome-wide maps of epigenomic marks and transcription factor binding provide complementary information for interpreting a subset of such prioritized variants. Here we developed the Constrained Non-Exonic Predictor (CNEP) to quantify the evidence of each base in the human genome being in a constrained non-exonic element from over 60,000 epigenomic and transcription factor binding features. We find that the CNEP score outperforms baseline and related existing scores at predicting constrained non-exonic bases from such data. However, a subset of such bases are still not well predicted by CNEP. We developed a complementary Conservation Signature Score by CNEP (CSS-CNEP) using conservation state and constrained element annotations that is predictive of those bases. Using human genetic variation, regulatory sequence motifs, mouse epigenomic data, and retrospectively considered additional human data we further characterize the nature of constrained non-exonic bases with low CNEP scores.

Functional consequences of genetic variation in sodium channel modifiers in early onset lone atrial fibrillation

2018 ◽  
Vol 15 (2) ◽  
pp. 93-102 ◽  
Author(s):  
Federico Denti ◽  
Christian Paludan-Müller ◽  
Søren-Peter Olesen ◽  
Stig Haunsø ◽  
Jesper Hastrup Svendsen ◽  
...  
Keyword(s):  
Atrial Fibrillation ◽  
Genetic Variation ◽  
Sodium Channel ◽  
Early Onset ◽  
Lone Atrial Fibrillation ◽  
Functional Consequences

scholarly journals The Rhizobium leguminosarum bv. trifolii RosR: Transcriptional Regulator Involved in Exopolysaccharide Production

2007 ◽  
Vol 20 (7) ◽  
pp. 867-881 ◽  
Author(s):  
Monika Janczarek ◽  
Anna Skorupska
Keyword(s):  
Binding Site ◽  
Rhizobium Leguminosarum ◽  
Upstream Region ◽  
Regulatory Sequence ◽  
Lacz Gene ◽  
Sequence Motifs ◽  
Exopolysaccharide Production ◽  
Promoter Sequences ◽  
E Coli ◽  
Multiple Copies

The acidic exopolysaccharide is required for the establishment of symbiosis between the nitrogen-fixing bacterium Rhizobium leguminosarum bv. trifolii and clover. Here, we describe RosR protein from R. leguminosarum bv. trifolii 24.2, a homolog of transcriptional regulators belonging to the family of Ros/MucR proteins. R. leguminosarum bv. trifolii RosR possesses a characteristic Cys2His2 type zincfinger motif in its C-terminal domain. Recombinant (His)6RosR binds to an RosR-box sequence located upstream of rosR. Deletion analysis of the rosR upstream region resulted in identification of two -35 to -10 promoter sequences, two conserved inverted palindromic pentamers that resemble the cAMP-CRP binding site of Escherichia coli, inverted repeats identified as a RosR binding site, and other regulatory sequence motifs. When assayed in E. coli, a transcriptional fusion of the cAMP-CRP binding site containing the rosR upstream region and lacZ gene was moderately responsive to glucose. The sensitivity of the rosR promoter to glucose was not observed in E. coli ΔcyaA. A rosR frame-shift mutant of R. leguminosarum bv. trifolii formed dry, wrinkled colonies and induced nodules on clover, but did not fix nitrogen. In the rosR mutant, transcription of pssA-lacZ fusion was decreased, indicating positive regulation of the pssA gene by RosR. Multiple copies of rosR in R. leguminosarum bv. trifolii 24.2 increased exopolysaccharide production.

scholarly journals Human polymorphisms in GSDMD alter the inflammatory response

2020 ◽  
Vol 295 (10) ◽  
pp. 3228-3238 ◽  
Author(s):  
Joseph K. Rathkey ◽  
Tsan S. Xiao ◽  
Derek W. Abbott
Keyword(s):  
Cell Death ◽  
Genetic Variation ◽  
Posttranslational Modifications ◽  
Apoptotic Cell ◽  
Gene Families ◽  
Inflammasome Activation ◽  
Caspase Cleavage ◽  
Immune Genes ◽  
Functional Consequences ◽  
Innate Immune Genes

Exomic studies have demonstrated that innate immune genes exhibit an even higher degree of variation than the majority of other gene families. However, the phenotypic implications of this genetic variation are not well understood, with effects ranging from hypomorphic to silent to hyperfunctioning. In this work, we study the functional consequences of this variation by investigating polymorphisms in gasdermin D, the key pyroptotic effector protein. We find that, although SNPs affecting potential posttranslational modifications did not affect gasdermin D function or pyroptosis, polymorphisms disrupting sites predicted to be structurally important dramatically alter gasdermin D function. The manner in which these polymorphisms alter function varies from conserving normal pyroptotic function to inhibiting caspase cleavage to disrupting oligomerization and pore formation. Further, downstream of inflammasome activation, polymorphisms that cause loss of gasdermin D function convert inflammatory pyroptotic cell death into immunologically silent apoptotic cell death. These findings suggest that human genetic variation can alter mechanisms of cell death in inflammation.

scholarly journals Role of Genetic Variation in ABC Transporters in Breast Cancer Prognosis and Therapy Response

2020 ◽  
Vol 21 (24) ◽  
pp. 9556
Author(s):  
Viktor Hlaváč ◽  
Radka Václavíková ◽  
Veronika Brynychová ◽  
Renata Koževnikovová ◽  
Katerina Kopečková ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Genetic Variation ◽  
Abc Transporters ◽  
Statistical Significance ◽  
Strong Support ◽  
Disease Free Survival ◽  
Cancer Prognosis ◽  
Future Research ◽  
Regulatory Sequences

Breast cancer is the most common cancer in women in the world. The role of germline genetic variability in ATP-binding cassette (ABC) transporters in cancer chemoresistance and prognosis still needs to be elucidated. We used next-generation sequencing to assess associations of germline variants in coding and regulatory sequences of all human ABC genes with response of the patients to the neoadjuvant cytotoxic chemotherapy and disease-free survival (n = 105). A total of 43 prioritized variants associating with response or survival in the above testing phase were then analyzed by allelic discrimination in the large validation set (n = 802). Variants in ABCA4, ABCA9, ABCA12, ABCB5, ABCC5, ABCC8, ABCC11, and ABCD4 associated with response and variants in ABCA7, ABCA13, ABCC4, and ABCG8 with survival of the patients. No association passed a false discovery rate test, however, the rs17822931 (Gly180Arg) in ABCC11, associating with response, and the synonymous rs17548783 in ABCA13 (survival) have a strong support in the literature and are, thus, interesting for further research. Although replicated associations have not reached robust statistical significance, the role of ABC transporters in breast cancer should not be ruled out. Future research and careful validation of findings will be essential for assessment of genetic variation which was not in the focus of this study, e.g., non-coding sequences, copy numbers, and structural variations together with somatic mutations.

A 5′ Regulatory Sequence Containing Two Ets Motifs Controls the Expression of the Wiskott-Aldrich Syndrome Protein (WASP) Gene in Human Hematopoietic Cells

Blood ◽  
1998 ◽  
Vol 91 (12) ◽  
pp. 4554-4560 ◽  
Author(s):  
A. Petrella ◽  
I. Doti ◽  
V. Agosti ◽  
P. Carandente Giarrusso ◽  
D. Vitale ◽  
...  
Keyword(s):  
Transcription Factors ◽  
Jurkat Cells ◽  
Regulatory Sequence ◽  
Regulatory Sequences ◽  
Specific Expression ◽  
Wiskott Aldrich Syndrome ◽  
Nuclear Extracts ◽  
Ets Family ◽  
Wasp Gene ◽  
Syndrome Protein

The recently-identified Wiskott-Aldrich syndrome protein gene (WASP) is responsible for the Wiskott-Aldrich X-linked immunodeficiency as well as for isolated X-linked thrombocytopenia (XLT). To characterize the regulatory sequences of the WASP gene, we have isolated, sequenced and functionally analyzed a 1.6-Kb DNA fragment upstream of the WASP coding sequence. Transfection experiments showed that this fragment is capable of directing efficient expression of the reporter chloramphenicol acetyltransferase (CAT) gene in all human hematopoietic cell lines tested. Progressive 5′ deletions showed that the minimal sequence required for hematopoietic-specific expression consists of 137 bp upstream of the transcription start site. This contains potential binding sites for several hematopoietic transcription factors and, in particular, two Ets-1 consensus that proved able to specifically bind to proteins present in nuclear extracts of Jurkat cells. Overexpression of Ets-1 in HeLa resulted in transactivation of the CAT reporter gene under the control of WASP regulatory sequences. Disruption of the Ets-binding sequences by side-directed mutagenesis abolished CAT expression in Jurkat cells, indicating that transcription factors of the Ets family play a key role in the control of WASP transcription.

scholarly journals Multiple factors regulating the expression of human thromboxane synthase gene

1996 ◽  
Vol 319 (3) ◽  
pp. 783-791 ◽  
Author(s):  
Kuan-Der LEE ◽  
Seung Joon BAEK ◽  
Rong-Fong SHEN
Keyword(s):  
Gene Expression ◽  
Reporter Gene ◽  
Promoter Activity ◽  
Reporter Gene Expression ◽  
Regulatory Sequence ◽  
Dependent Manner ◽  
Cis Elements ◽  
Thromboxane Synthase ◽  
Multiple Factors ◽  
Repressive Effect

Characterization of the 5.5 kb promoter of human thromboxane synthase (TS) gene revealed a proximal positive regulatory sequence (PPRS, -90 to -25 bp) and several distal repressive elements. The maximal promoter activity was found to reside within the first 285 bp, ∼75% of which was contributed by the PPRS. The sequence between -365 and -665 bp exerted a strong repressive effect (∼55%) on reporter gene expression independent of orientation and position, consistent with properties expected for a silencer. The sequence upstream of -665 bp to -5.5 kb contains mainly repressive elements which further reduce the promoter activity by 30%. The 65 bp PPRS worked in an orientation-independent, but position-dependent, manner and could be further divided into two independent elements, PPRS1 (-90 to -50 bp) and PPRS2 (-50 to -25 bp). While similar nuclear factor(s) from different cell types interact with PPRS2, those interacting with PPRS1 exhibit cell specificity. Internal sequence deletion and oligonucleotide competition established that a binding sequence for NF-E2 in PPRS1 (-60 tgctgattcat -50) was important for enhancing TS promoter activity in HL-60 cells. The presence of NF-E2 mRNA in HL-60 cells was demonstrated by reverse-transcription PCR amplification of the cDNA and Northern blot analysis. A 9-fold transactivation of luciferase (luc) reporter gene expression had been detected when NF-E2 cDNA was co-expressed with a TS promoter/luc construct. Despite the fact that NF-E2 and the cis-elements could alter the efficiency of TS transcription, they were not sufficient for restricting cell-specific TS expression. Analysis of the methylation status at the TS promoter in several human cell lines reveals cell-specific patterns of methylation that might correlate with TS expression. Taken together, these results suggest that the expression of human TS gene is modulated by multiple factors including cis-elements, trans-activator(s), and possibly genomic methylation.

Protein:DNA interactions at chromosomal loop attachment sites

Genome ◽  
1989 ◽  
Vol 31 (2) ◽  
pp. 503-509 ◽  
Author(s):  
Veronica C. Blasquez ◽  
Ann O. Sperry ◽  
Peter N. Cockerill ◽  
William T. Garrard
Keyword(s):  
Nuclear Matrix ◽  
Binding Sites ◽  
Topoisomerase Ii ◽  
Regulatory Sequences ◽  
Immunoglobulin Gene ◽  
Sequence Motifs ◽  
Cis Acting ◽  
Consensus Sequences ◽  
Dna And Rna ◽  
Multiple Binding Sites

We have recently identified an evolutionarily conserved class of sequences that organize chromosomal loops in the interphase nucleus, which we have termed "matrix association regions" (MARs). MARs are about 200 bp long, AT-rich, contain topoisomerase II consensus sequences and other AT-rich sequence motifs, often reside near cis-acting regulatory sequences, and their binding sites are abundant (> 10 000 per mammalian nucleus). Here we demonstrate that the interactions between the mouse κ immunoglobulin gene MAR and topoisomerase II or the "nuclear matrix" occur between multiple and sometimes overlapping binding sites. Interestingly, the sites most susceptible to topoisomerase II cleavage are localized near the breakpoints of a previously described illegitimate recombination event. The presence of multiple binding sites within single MARs may allow DNA and RNA polymerase passage without disrupting primary loop organization.Key words: MARs, chromatin loops, topoisomerase II, nuclear matrix.

scholarly journals Unusually Low Levels of Genetic Variation among Giardia lamblia Isolates

2007 ◽  
Vol 6 (8) ◽  
pp. 1421-1430 ◽  
Author(s):  
Smilja Teodorovic ◽  
John M. Braverman ◽  
Heidi G. Elmendorf
Keyword(s):  
Genetic Diversity ◽  
Genetic Variation ◽  
Giardia Lamblia ◽  
Diarrheal Disease ◽  
Regulation Of Gene Expression ◽  
Genetic Exchange ◽  
Disease Etiology ◽  
Noncoding Regions ◽  
Low Genetic Diversity ◽  
Low Levels

ABSTRACT Giardia lamblia, an intestinal pathogen of mammals, including humans, is a significant cause of diarrheal disease around the world. Additionally, the parasite is found on a lineage which separated early from the main branch in eukaryotic evolution. The extent of genetic diversity among G. lamblia isolates is insufficiently understood, but this knowledge is a prerequisite to better understand the role of parasite variation in disease etiology and to examine the evolution of mechanisms of genetic exchange among eukaryotes. Intraisolate genetic variation in G. lamblia has never been estimated, and previous studies on interisolate genetic variation have included a limited sample of loci. Here we report a population genetics study of intra- and interisolate genetic diversity based on six coding and four noncoding regions from nine G. lamblia isolates. Our results indicate exceedingly low levels of genetic variation in two out of three G. lamblia groups that infect humans; this variation is sufficient to allow identification of isolate-specific markers. Low genetic diversity at both coding and noncoding regions, with an overall bias towards synonymous substitutions, was discovered. Surprisingly, we found a dichotomous haplotype structure in the third, more variable G. lamblia group, represented by a haplotype shared with one of the homogenous groups and an additional group-specific haplotype. We propose that the distinct patterns of genetic-variation distribution among lineages are a consequence of the presence of genetic exchange. More broadly, our findings have implications for the regulation of gene expression, as well as the mode of reproduction in the parasite.

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