scholarly journals Emerging Functions of Transcription Factors in Malaria Parasite

2011 ◽  
Vol 2011 ◽  
pp. 1-6 ◽  
Author(s):  
Renu Tuteja ◽  
Abulaish Ansari ◽  
Virander Singh Chauhan
Keyword(s):  
Gene Expression ◽  
Transcription Factors ◽  
Rna Polymerase ◽  
Malaria Parasite ◽  
Transcriptional Control ◽  
Regulation Of Gene Expression ◽  
High Mobility ◽  
High Mobility Group Protein ◽  
Eukaryotic Genes ◽  
Group Protein

Transcription is a process by which the genetic information stored in DNA is converted into mRNA by enzymes known as RNA polymerase. Bacteria use only one RNA polymerase to transcribe all of its genes while eukaryotes contain three RNA polymerases to transcribe the variety of eukaryotic genes. RNA polymerase also requires other factors/proteins to produce the transcript. These factors generally termed as transcription factors (TFs) are either associated directly with RNA polymerase or add in building the actual transcription apparatus. TFs are the most common tools that our cells use to control gene expression.Plasmodium falciparumis responsible for causing the most lethal form of malaria in humans. It shows most of its characteristics common to eukaryotic transcription but it is assumed that mechanisms of transcriptional control inP. falciparumsomehow differ from those of other eukaryotes. In this article we describe the studies on the main TFs such as myb protein, high mobility group protein and ApiA2 family proteins from malaria parasite. These studies show that these TFs are slowly emerging to have defined roles in the regulation of gene expression in the parasite.

scholarly journals Functional roles of the transcription factor Oct-2A and the high mobility group protein I/Y in HLA-DRA gene expression.

1995 ◽  
Vol 182 (2) ◽  
pp. 487-500 ◽  
Author(s):  
S A Abdulkadir ◽  
S Krishna ◽  
D Thanos ◽  
T Maniatis ◽  
J L Strominger ◽  
...  
Keyword(s):  
Gene Expression ◽  
Transcription Factor ◽  
B Cells ◽  
B Cell ◽  
Cell Lines ◽  
High Mobility ◽  
High Mobility Group ◽  
High Mobility Group Protein ◽  
Ifn Gamma ◽  
Group Protein

The class II major histocompatibility complex gene HLA-DRA is expressed in B cells, activated T lymphocytes, and in antigen-presenting cells. In addition, HLA-DRA gene expression is inducible in a variety of cell types by interferon-gamma (IFN-gamma). Here we show that the lymphoid-specific transcription factor Oct-2A plays a critical role in HLA-DRA gene expression in class II-positive B cell lines, and that the high mobility group protein (HMG) I/Y binds to multiple sites within the DRA promoter, including the Oct-2A binding site. Coexpression of HMG I/Y and Oct-2 in cell lines lacking Oct-2 results in high levels of HLA-DRA gene expression, and in vitro DNA-binding studies reveal that HMG I/Y stimulates Oct-2A binding to the HLA-DRA promoter. Thus, Oct-2A and HMG I/Y may synergize to activate HLA-DRA expression in B cells. By contrast, Oct-2A is not involved in the IFN-gamma induction of the HLA-DRA gene in HeLa cells, but antisense HMG I/Y dramatically decreases the level of induction. We conclude that distinct sets of transcription factors are involved in the two modes of HLA-DRA expression, and that HMG I/Y may be important for B cell-specific expression, and is essential for IFN-gamma induction.

scholarly journals DksA-dependent regulation of RpoS contributes to Borrelia burgdorferi tick-borne transmission and mammalian infectivity

2021 ◽  
Vol 17 (2) ◽  
pp. e1009072
Author(s):  
William K. Boyle ◽  
Crystal L. Richards ◽  
Daniel P. Dulebohn ◽  
Amanda K. Zalud ◽  
Jeff A. Shaw ◽  
...  
Keyword(s):  
Gene Expression ◽  
Transcription Factors ◽  
Rna Polymerase ◽  
Nutrient Limitation ◽  
Pathogenic Bacteria ◽  
Transcriptional Control ◽  
Ixodes Scapularis ◽  
Stringent Response ◽  
Transcriptional Responses

Throughout its enzootic cycle, the Lyme disease spirochete Borreliella (Borrelia) burgdorferi, senses and responds to changes in its environment using a small repertoire of transcription factors that coordinate the expression of genes required for infection of Ixodes ticks and various mammalian hosts. Among these transcription factors, the DnaK suppressor protein (DksA) plays a pivotal role in regulating gene expression in B. burgdorferi during periods of nutrient limitation and is required for mammalian infectivity. In many pathogenic bacteria, the gene regulatory activity of DksA, along with the alarmone guanosine penta- and tetra-phosphate ((p)ppGpp), coordinate the stringent response to various environmental stresses, including nutrient limitation. In this study, we sought to characterize the role of DksA in regulating the transcriptional activity of RNA polymerase and its role in the regulation of RpoS-dependent gene expression required for B. burgdorferi infectivity. Using in vitro transcription assays, we observed recombinant DksA inhibits RpoD-dependent transcription by B. burgdorferi RNA polymerase independent of ppGpp. Additionally, we determined the pH-inducible expression of RpoS-dependent genes relies on DksA, but this relationship is independent of (p)ppGpp produced by Relbbu. Subsequent transcriptomic and western blot assays indicate DksA regulates the expression of BBD18, a protein previously implicated in the post-transcriptional regulation of RpoS. Moreover, we observed DksA was required for infection of mice following intraperitoneal inoculation or for transmission of B. burgdorferi by Ixodes scapularis nymphs. Together, these data suggest DksA plays a central role in coordinating transcriptional responses in B. burgdorferi required for infectivity through DksA’s interactions with RNA polymerase and post-transcriptional control of RpoS.

Abstract 350: High-Mobility Group Protein B2 is Essential in Maintaining Normal Cardiac Gene Expression

2014 ◽  
Vol 115 (suppl_1) ◽  
Author(s):  
Haodong Chen ◽  
Manuel Rosa-Garrido ◽  
Ricardo Gray ◽  
Zugen Chen ◽  
Stanley F Nelson ◽  
...  
Keyword(s):  
Gene Expression ◽  
Binding Sites ◽  
Gene Expression Pattern ◽  
High Mobility ◽  
High Mobility Group Protein ◽  
Hypertrophic Growth ◽  
Knock Down ◽  
Intergenic Regions ◽  
Cardiac Gene ◽  
Group Protein

Heart hypertrophy is a complex disease that involves differential expression of hundreds of genes and requires highly coordinated chromatin remodeling events that must facilitate such genome-wide changes in gene expression. We examine the genome-wide distribution of a chromatin structural protein, High-Mobility Group Protein B2 (HMGB2) in isolated cardiac myocytes with or without adrenergic receptor agonist. We report a comprehensive map of HMGB2 binding in both normal and hypertrophic cardiac myocytes, and find that HMGB2 preferentially localizes to promoters, CpG islands, enhancers and transcription factor binding sites. Moreover, we find that upon hypertrophic stimulation, HMGB2 peaks move from regulatory elements to intergenic regions. Because both HMGB2 knock-down and PHE treatment can induce hypertrophic growth, we compare gene expression dynamics between HMGB2 knock-down and PHE treatment, and find hypertrophy-related gene expression pattern upon HMGB2 knock-down is different from the one after PHE treatment. This also indicates the existence of multiple pathways that lead to hypertrophic growth. Further study reveals that HMGB2 co-localizes with many other functional elements including p300 and CTCF. Interestingly, we find that HMGB2 binding profiles are different at the binding sites of four cardiac transcription factors, MEF2A, NKX2.5, GATA4 and SRF. More specifically, HMGB2 localization is higher at MEF2A binding sites, indicating that HMGB2 may be involved in facilitating the functioning of MEF2A. Finally, we calculate the DNA bendability score based on the primary sequence of genome and correlate it with HMGB2 binding intensity. Consistent with the understanding that HMGB2 bends DNA toward DNA major groove, we find a positive correlation between HMGB2 binding and DNA bending propensity. Surprisingly, PHE treatment in NRVMs induced the relocation of HMGB2 to less bendable intergenic regions. Taken together, our data conclude that HMGB2 is required for maintaining the normal cardiac gene expression pattern, and its binding to cardiac chromatin is dynamically altered during hypertrophic growth.

scholarly journals Intra- and intermolecular cooperative binding of high-mobility-group protein I(Y) to the beta-interferon promoter.

1997 ◽  
Vol 17 (7) ◽  
pp. 3649-3662 ◽  
Author(s):  
J Yie ◽  
S Liang ◽  
M Merika ◽  
D Thanos
Keyword(s):  
Protein Interactions ◽  
Binding Sites ◽  
Specific Binding ◽  
High Mobility ◽  
High Mobility Group ◽  
High Mobility Group Protein ◽  
Beta Interferon ◽  
Eukaryotic Genes ◽  
Group Protein

The mammalian high-mobility-group protein I(Y) [HMG I(Y)], while not a typical transcriptional activator, is required for the expression of many eukaryotic genes. HMG I(Y) appears to recruit and stabilize complexes of transcriptional activators through protein-DNA and protein-protein interactions. The protein binds to the minor groove of DNA via three short basic repeats, preferring tracts of adenines and thymines arranged on the same face of the DNA helix. However, the mode by which these three basic repeats function together to recognize HMG I(Y) binding sites has remained unclear. Here, using deletion mutants of HMG I(Y), DNase I footprinting, methylation interference, and in vivo transcriptional assays, we have characterized the binding of HMG I(Y) to the model beta-interferon enhancer. We show that two molecules of HMG I(Y) bind to the enhancer in a highly cooperative fashion, each molecule using a distinct pair of basic repeats to recognize the tandem AT-rich regions of the binding sites. We have also characterized the function of each basic repeat, showing that only the central repeat accounts for specific DNA binding and that the presence of a second repeat bound to an adjacent AT-rich region results in intramolecular cooperativity in binding. Surprisingly, the carboxyl-terminal acidic tail of HMG I(Y) is also important for specific binding in the context of the full-length protein. Our results present a detailed examination of HMG I(Y) binding in an important biological context, which can be extended not only to HMG I(Y) binding in other systems but also to the binding mode of many other proteins containing homologous basic repeats, which have been conserved from bacteria to humans.

Nutrient-regulated gene expression in eukaryotes

2006 ◽  
Vol 73 ◽  
pp. 85-96 ◽  
Author(s):  
Richard J. Reece ◽  
Laila Beynon ◽  
Stacey Holden ◽  
Amanda D. Hughes ◽  
Karine Rébora ◽  
...  
Keyword(s):  
Gene Expression ◽  
Rna Polymerase ◽  
Rna Polymerase Ii ◽  
Transcriptional Control ◽  
Direct Interaction ◽  
Signalling Pathways ◽  
A Cell ◽  
One Step ◽  
Higher Eukaryotes ◽  
Regulated Gene Expression

The recognition of changes in environmental conditions, and the ability to adapt to these changes, is essential for the viability of cells. There are numerous well characterized systems by which the presence or absence of an individual metabolite may be recognized by a cell. However, the recognition of a metabolite is just one step in a process that often results in changes in the expression of whole sets of genes required to respond to that metabolite. In higher eukaryotes, the signalling pathway between metabolite recognition and transcriptional control can be complex. Recent evidence from the relatively simple eukaryote yeast suggests that complex signalling pathways may be circumvented through the direct interaction between individual metabolites and regulators of RNA polymerase II-mediated transcription. Biochemical and structural analyses are beginning to unravel these elegant genetic control elements.

scholarly journals HMGA1 Is a Potential Driver of Preeclampsia Pathogenesis by Interference with Extravillous Trophoblasts Invasion

Biomolecules ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 822
Author(s):  
Keiichi Matsubara ◽  
Yuko Matsubara ◽  
Yuka Uchikura ◽  
Katsuko Takagi ◽  
Akiko Yano ◽  
...  
Keyword(s):  
Protein A ◽  
High Mobility ◽  
Extravillous Trophoblast ◽  
High Mobility Group Protein ◽  
Successful Pregnancy ◽  
Group Protein ◽  
Serious Disease ◽  
Proliferation And Invasion ◽  
Extravillous Trophoblasts ◽  
Fertilized Egg

Preeclampsia (PE) is a serious disease that can be fatal for the mother and fetus. The two-stage theory has been proposed as its cause, with the first stage comprising poor placentation associated with the failure of fertilized egg implantation. Successful implantation and placentation require maternal immunotolerance of the fertilized egg as a semi-allograft and appropriate extravillous trophoblast (EVT) invasion of the decidua and myometrium. The disturbance of EVT invasion during implantation in PE results in impaired spiral artery remodeling. PE is thought to be caused by hypoxia during remodeling failure–derived poor placentation, which results in chronic inflammation. High-mobility group protein A (HMGA) is involved in the growth and invasion of cancer cells and likely in the growth and invasion of trophoblasts. Its mechanism of action is associated with immunotolerance. Thus, HMGA is thought to play a pivotal role in successful pregnancy, and its dysfunction may be related to the pathogenesis of PE. The evaluation of HMGA function and its changes in PE might confirm that it is a reliable biomarker of PE and provide prospects for PE treatment through the induction of EVT proliferation and invasion during the implantation.

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