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Multiple Transcription Factors (multiple + transcription_factor)
Selected AbstractsBioenergetics and the epigenome: Interface between the environment and genes in common diseasesDEVELOPMENTAL DISABILITIES RESEARCH REVIEW, Issue 2 2010Douglas C. Wallace Abstract Extensive efforts have been directed at using genome-wide association studies (GWAS) to identify the genes responsible for common metabolic and degenerative diseases, cancer, and aging, but with limited success. While environmental factors have been evoked to explain this conundrum, the nature of these environmental factors remains unexplained. The availability of and demands for energy constitute one of the most important aspects of the environment. The flow of energy through the cell is primarily mediated by the mitochondrion, which oxidizes reducing equivalents from hydrocarbons via acetyl-CoA, NADH + H+, and FADH2 to generate ATP through oxidative phosphorylation (OXPHOS). The mitochondrial genome encompasses hundreds of nuclear DNA (nDNA)-encoded genes plus 37 mitochondrial DNA (mtDNA)-encoded genes. Although the mtDNA has a high mutation rate, only milder, potentially adaptive mutations are introduced into the population through female oocytes. In contrast, nDNA-encoded bioenergetic genes have a low mutation rate. However, their expression is modulated by histone phosphorylation and acetylation using mitochondrially-generated ATP and acetyl-CoA, which permits increased gene expression, growth, and reproduction when calories are abundant. Phosphorylation, acetylaton, and cellular redox state also regulate most signal transduction pathways and activities of multiple transcription factors. Thus, mtDNA mutations provide heritable and stable adaptation to regional differences while mitochondrially-mediated changes in the epigenome permit reversible modulation of gene expression in response to fluctuations in the energy environment. The most common genomic changes that interface with the environment and cause complex disease must, therefore, be mitochondrial and epigenomic in origin. © 2010 Wiley-Liss, Inc. Dev Disabil Res Rev 2010;16:114,119. [source] Prokaryotic genome regulation: multifactor promoters, multitarget regulators and hierarchic networksFEMS MICROBIOLOGY REVIEWS, Issue 5 2010Akira Ishihama Abstract The vast majority of experimental data have been accumulated on the transcription regulation of individual genes within a single model prokaryote, Escherichia coli, which form the well-established on,off switch model of transcription by DNA-binding regulatory proteins. After the development of modern high-throughput experimental systems such as microarray analysis of whole genome transcription and the Genomic SELEX search for the whole set of regulation targets by transcription factors, a number of E. coli promoters are now recognized to be under the control of multiple transcription factors, as in the case of eukaryotes. The number of regulation targets of a single transcription factor has also been found to be more than hitherto recognized, ranging up to hundreds of promoters, genes or operons for several global regulators. The multifactor promoters and the multitarget transcription factors can be assembled into complex networks of transcription regulation, forming hierarchical networks. [source] Defining ETS transcription regulatory networks and their contribution to breast cancer progressionJOURNAL OF CELLULAR BIOCHEMISTRY, Issue 3 2007David P. Turner Abstract ETS factors are members of one of the largest families of evolutionarily conserved transcription factors, regulating critical functions in normal cell homeostasis, that when perturbed contribute to tumor progression. The well documented alterations in ETS factor expression and function during breast cancer progression result in pleiotropic effects manifested by the downstream effect on their target genes. Multiple ETS factors bind to the same regulatory sites present on target genes, suggesting redundant or competitive functions. Furthermore, additional events contribute to, or may be necessary for, target gene regulation. In order to advance our understanding of the ETS-dependent regulation of breast cancer progression and metastasis, this prospect article puts forward a model for examining the effects of simultaneous expression of multiple transcription factors on the transcriptome of non-metastatic and metastatic breast cancer. Compared to existing RNA profiles defined following expression of individual transcription factors, the anti- and pro-metastatic signatures obtained by examining specific ETS regulatory networks will significantly improve our ability to accurately predict tumor progression and advance our understanding of gene regulation in cancer. Coordination of multiple ETS gene functions also mediates interactions between tumor and stromal cells and thus contributes to the cancer phenotype. As such, these new insights may provide a novel view of the ETS gene family as well as a focal point for studying the complex biological control involved in tumor progression. J. Cell. Biochem. 102: 549,559, 2007. © 2007 Wiley-Liss, Inc. [source] Stimulation of macrophage TNF, production by orthopaedic wear particles requires activation of the ERK1/2/Egr-1 and NF-,B pathways but is independent of p38 and JNKJOURNAL OF CELLULAR PHYSIOLOGY, Issue 3 2008Michelle A. Beidelschies Bone loss that causes aseptic loosening of orthopedic implants is initiated by pro-inflammatory cytokines produced by macrophages in response to implant-derived wear particles. MAPK and NF-,B signaling pathways are activated by the particles; however, it is not clear which of the signaling pathways are important for the initial response to the wear particles and which are only involved at later steps in the process, such as osteoclast differentiation. Here, we show that the ERK1/2, p38, JNK, and NF-,B pathways are rapidly activated by the wear particles but that only the ERK1/2 and NF-,B pathways are required for the initial response to the wear particles, which include increases in TNF, promoter activity, TNF, mRNA expression, and secretion of TNF, protein. Moreover, ERK1/2 activation by wear particles is also required for increased expression of the transcription factor Egr-1 as well as Egr-1's ability to bind to and activate the TNF, promoter. These results, together with our previous studies of the PI3K/Akt pathway, demonstrate that wear particles coordinately activate multiple signaling pathways and multiple transcription factors to stimulate production of pro-inflammatory cytokines, such as TNF,. The current study also demonstrates that the signaling pathways are activated to a much greater extent by wear particles with adherent endotoxin than by "endotoxin-free" wear particles. These results, together with those demonstrating the requirement for ERK1/2/Egr-1 and NF-,B, show that activation of these signaling pathways is responsible for the ability of adherent endotoxin to potentiate cytokine production, osteoclast differentiation, and bone loss induced by wear particles. J. Cell. Physiol. 217: 652,666, 2008. © 2008 Wiley-Liss, Inc. [source] Overexpression of c-Fos is sufficient to stimulate tyrosine hydroxylase (TH) gene transcription in rat pheochromocytoma PC18 cellsJOURNAL OF NEUROCHEMISTRY, Issue 2 2002Baoyong Sun Abstract The AP1 site within the tyrosine hydroxylase gene proximal promoter is essential for the response of the gene to numerous stimuli. Stimulation of this gene is often associated with induction of the AP1 transcription factor, c-Fos. However, many stimuli activate or induce multiple transcription factors that interact with this AP1 site or other sites within the gene's proximal promoter. Hence, it remains unclear whether c-Fos induction by itself is sufficient to stimulate the tyrosine hydroxylase gene. In this study we produce rat pheochromocytoma PC18 cells that overexpress c-Fos under control of the tet-inducible system. We demonstrate that induction of c-Fos leads to dramatic stimulation of tyrosine hydroxylase gene transcription rate measured using nuclear run-on assays. This stimulation is closely associated quantitatively with the induction of c-Fos and does not apparently require phosphorylation of c-Fos. The response is partially dependent on the AP1 site within the tyrosine hydroxylase proximal promoter. However, the response of the proximal promoter to c-Fos induction is relatively small compared with that of the endogenous gene. Consequently, our results suggest that c-Fos exerts its influence on the tyrosine hydroxylase gene via multiple mechanisms that are dependent and independent of the proximal promoter AP1 site. [source] Structure of the Taz2 domain of p300: insights into ligand bindingACTA CRYSTALLOGRAPHICA SECTION D, Issue 12 2009Maria Miller CBP and its paralog p300 are histone acetyl transferases that regulate gene expression by interacting with multiple transcription factors via specialized domains. The structure of a segment of human p300 protein (residues 1723,1836) corresponding to the extended zinc-binding Taz2 domain has been investigated. The crystal structure was solved by the SAD approach utilizing the anomalous diffraction signal of the bound Zn ions. The structure comprises an atypical helical bundle stabilized by three Zn ions and closely resembles the solution structures determined previously for shorter peptides. Residues 1813,1834 from the current construct form a helical extension of the C-terminal helix and make extensive crystal-contact interactions with the peptide-binding site of Taz2, providing additional insights into the mechanism of the recognition of diverse transactivation domains (TADs) by Taz2. On the basis of these results and molecular modeling, a hypothetical model of the binding of phosphorylated p53 TAD1 to Taz2 has been proposed. [source] | ||||||||||