The Experts below are selected from a list of 18081 Experts worldwide ranked by ideXlab platform
Timothy F. Osborne - One of the best experts on this subject based on the ideXlab platform.
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different sterol regulatorY element binding protein 1 isoforms utilize distinct co regulatorY Factors to activate the promoter for fattY acid sYnthase
Journal of Biological Chemistry, 2000Co-Authors: Marisa M Magana, Seung Hoi Koo, Howard C Towle, Timothy F. OsborneAbstract:Abstract Sterol regulatorY element-binding proteins (SREBPs) activate genes of cholesterol and fattY acid metabolism. In each case, a ubiquitous co-regulatorY Factor that binds to a neighboring recognition site is also required for efficient promoter activation. It is likelY that gene- and pathwaY-specific regulation bY the separate SREBP isoforms is dependent on subtle differences in how the individual proteins function with specific co-regulators to activate gene expression. In the studies reported here we extend these observations significantlY bY demonstrating that SREBPs are involved in both sterol regulation and carbohYdrate activation of the FAS promoter. We also demonstrate that the previouslY implicated Sp1 site is largelY dispensable for sterol regulation in established cultured cells, whereas a CCAAT-binding Factor/Nuclear Factor Y is criticallY important. In contrast, carbohYdrate activation of the FAS promoter in primarY hepatocYtes is dependent upon SREBP and both the Sp1 and CCAAT-binding Factor/Nuclear Factor Y sites. Because 1c is the predominant SREBP isoform expressed in hepatocYtes and 1a is more abundant in sterol depleted established cell lines, this suggests that the different SREBP isoforms utilize distinct co-regulatorY Factors to activate target gene expression.
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Sterol Regulation of 3-HYdroxY-3-MethYlglutarYl-coenzYme A SYnthase Gene through a Direct Interaction Between Sterol RegulatorY Element Binding Protein and the Trimeric CCAAT-binding Factor/Nuclear Factor Y
The Journal of biological chemistry, 1998Co-Authors: Kimberly A. Dooley, Shawn Millinder, Timothy F. OsborneAbstract:Abstract 3-HYdroxY-3-methYlglutarYl-coenzYme A (HMG-CoA) sYnthase, a keY regulatorY enzYme in the pathwaY for endogenous cholesterol sYnthesis, is a target for negative feedback regulation bY cholesterol. The promoter for HMG-CoA sYnthase contains two binding sites for the sterol regulatorY element-binding proteins (SREBPs). When cellular sterol levels are low, the SREBPs are released from the endoplasmic reticulum membrane, allowing them to translocate to the nucleus and activate SREBP target genes. In all SREBP-regulated promoters studied to date, additional co-regulatorY transcription Factors are required. In the HMG-CoA sYnthase promoter there are several potential co-regulatorY transcription Factor binding sites, including an inverted CCAAT box. A similar element has been shown to function with SREBP to mediate sterol regulation of another gene involved in cholesterol metabolism, farnesYl diphosphate sYnthase. Here, we show that CCAAT binding Factor/Nuclear Factor Y (CBF/NF-Y) binding to the CCAAT box is required for sterol-regulated transcription of HMG-CoA sYnthase. The SREBP sites and the inverted CCAAT box are normallY separated bY 17 base pairs, and we show that increasing this distance results in a decrease in the level of transcriptional regulation bY sterols. Furthermore, we provide evidence that there is a direct interaction between CBF/NF-Y and the basic helix-loop-helix-zipper region of SREBP. InterestinglY, this interaction does not occur efficientlY with anY of the isolated subunits and appears to require all three nonidentical CBF/NF-Y subunits in a preassembled complex. Since CBF/NF-Y onlY binds to DNA when all three subunits are in a complex, this would prevent SREBP from forming nonproductive associations with the individual subunits.
Susan P. C. Cole - One of the best experts on this subject based on the ideXlab platform.
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Characterization of the human topoisomerase IIβ (TOP2B) promoter activitY: essential roles of the Nuclear Factor-Y (NF-Y)- and specificitY protein-1 (Sp1)-binding sites
Biochemical Journal, 2002Co-Authors: Chun-nam Lok, Alexander J. Lang, Shelagh E. L. Mirski, Susan P. C. ColeAbstract:EukarYotic topoisomerase II (topo II) catalYses topological genomic changes essential for chromosome segregation, chromatin reorganization, DNA replication and transcription. Mammalian topo II exists as two isoforms, designated alpha and beta. Human topo IIalpha is an important cancer drug target, and an established determinant of drug sensitivitY and resistance. Human topo IIbeta is also the target of anticancer drugs but its role in drug resistance is less clear. The two human topo II proteins are encoded bY the TOP2A and TOP2B genes, respectivelY, which despite their highlY conserved structural organization, are subject to distinctlY different modes of regulation. In the present studY, we have cloned and characterized the human TOP2B promoter containing a 1.3 kb fragment of the 5'-flanking and untranslated region (-1067 to +193). We found that the promoter activitY of this TOP2B fragment was constant throughout the cell cYcle, in contrast to the activitY of the proximal promoter of TOP2A which was low in resting cells and enhanced during proliferation. AnalYses of 5'-seriallY and internallY deleted luciferase reporter constructs revealed that 80% of the TOP2B promoter activitY could be attributed to the region between -533 and -481. Mutational analYses of putative regulatorY elements indicated that two inverted CCAAT boxes (ICBs) within this region were essential for TOP2B promoter activitY and gel mobilitY-shift assaYs indicated these sites bound the transcription Factor Nuclear Factor-Y (NF-Y). Co-transfection experiments using a dominant-negative form of subunit A of NF-Y suggested that TOP2B promoter activitY required direct interaction of NF-Y with the ICBs. In addition, a specificitY protein-1 (Sp1)-binding GC box located just upstream of the ICBs was shown to contribute to TOP2B promoter activitY in a sYnergistic manner with the ICBs. Our results suggest that the binding sites for NF-Y and Sp1 are critical for TOP2B transcription.
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Characterization of the human topoisomerase IIbeta (TOP2B) promoter activitY: essential roles of the Nuclear Factor-Y (NF-Y)- and specificitY protein-1 (Sp1)-binding sites.
The Biochemical journal, 2002Co-Authors: Chun-nam Lok, Alexander J. Lang, Shelagh E. L. Mirski, Susan P. C. ColeAbstract:EukarYotic topoisomerase II (topo II) catalYses topological genomic changes essential for chromosome segregation, chromatin reorganization, DNA replication and transcription. Mammalian topo II exists as two isoforms, designated alpha and beta. Human topo IIalpha is an important cancer drug target, and an established determinant of drug sensitivitY and resistance. Human topo IIbeta is also the target of anticancer drugs but its role in drug resistance is less clear. The two human topo II proteins are encoded bY the TOP2A and TOP2B genes, respectivelY, which despite their highlY conserved structural organization, are subject to distinctlY different modes of regulation. In the present studY, we have cloned and characterized the human TOP2B promoter containing a 1.3 kb fragment of the 5'-flanking and untranslated region (-1067 to +193). We found that the promoter activitY of this TOP2B fragment was constant throughout the cell cYcle, in contrast to the activitY of the proximal promoter of TOP2A which was low in resting cells and enhanced during proliferation. AnalYses of 5'-seriallY and internallY deleted luciferase reporter constructs revealed that 80% of the TOP2B promoter activitY could be attributed to the region between -533 and -481. Mutational analYses of putative regulatorY elements indicated that two inverted CCAAT boxes (ICBs) within this region were essential for TOP2B promoter activitY and gel mobilitY-shift assaYs indicated these sites bound the transcription Factor Nuclear Factor-Y (NF-Y). Co-transfection experiments using a dominant-negative form of subunit A of NF-Y suggested that TOP2B promoter activitY required direct interaction of NF-Y with the ICBs. In addition, a specificitY protein-1 (Sp1)-binding GC box located just upstream of the ICBs was shown to contribute to TOP2B promoter activitY in a sYnergistic manner with the ICBs. Our results suggest that the binding sites for NF-Y and Sp1 are critical for TOP2B transcription.
Sarawut Jitrapakdee - One of the best experts on this subject based on the ideXlab platform.
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Involvement of specific proteins (Sp1/Sp3) and Nuclear Factor Y in basal transcription of the distal promoter of the rat pYruvate carboxYlase gene in β-cells ☆
Biochemical and biophysical research communications, 2005Co-Authors: Piyanate Sunyakumthorn, Thirajit Boonsaen, Vichai Boonsaeng, John C. Wallace, Sarawut JitrapakdeeAbstract:Abstract PYruvate carboxYlase plaYs diverse roles in different biosYnthetic pathwaYs, including glucose-induced insulin secretion in pancreatic β-cells. We have localized the control region of the P2 promoter bY generating a series of 5′-nested deletion constructs, and both 25- and 9-bp internal deletion constructs, as well as bY performing site-directed mutagenesis. Transient transfections of these constructs into INS-1 cells identified a CCAAT box and a GC box that are located at −65/−61 and −48/−41, respectivelY, as the important determinants. Disruption of the GC box resulted in a 4-fold reduction of the reporter activitY, while disruption of the proximal CCAAT box (−65/−61) but not the distal CCAAT box (−95/−91) increased the reporter activitY bY 3-fold. Simultaneous disruptions of both the GC box and the CCAAT box reduced the reporter activitY to a level that was close to that of the single GC box mutation. Electrophoretic mobilitY shift assaYs (EMSAs) and supershift EMSAs using Nuclear extract from INS-1 cells demonstrated that Sp1 and Sp3 bind a GC box while the Nuclear Factor Y was shown to bind the proximal but not the distal CCAAT box.
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involvement of specific proteins sp1 sp3 and Nuclear Factor Y in basal transcription of the distal promoter of the rat pYruvate carboxYlase gene in β cells
Biochemical and Biophysical Research Communications, 2005Co-Authors: Piyanate Sunyakumthorn, Thirajit Boonsaen, Vichai Boonsaeng, John C. Wallace, Sarawut JitrapakdeeAbstract:Abstract PYruvate carboxYlase plaYs diverse roles in different biosYnthetic pathwaYs, including glucose-induced insulin secretion in pancreatic β-cells. We have localized the control region of the P2 promoter bY generating a series of 5′-nested deletion constructs, and both 25- and 9-bp internal deletion constructs, as well as bY performing site-directed mutagenesis. Transient transfections of these constructs into INS-1 cells identified a CCAAT box and a GC box that are located at −65/−61 and −48/−41, respectivelY, as the important determinants. Disruption of the GC box resulted in a 4-fold reduction of the reporter activitY, while disruption of the proximal CCAAT box (−65/−61) but not the distal CCAAT box (−95/−91) increased the reporter activitY bY 3-fold. Simultaneous disruptions of both the GC box and the CCAAT box reduced the reporter activitY to a level that was close to that of the single GC box mutation. Electrophoretic mobilitY shift assaYs (EMSAs) and supershift EMSAs using Nuclear extract from INS-1 cells demonstrated that Sp1 and Sp3 bind a GC box while the Nuclear Factor Y was shown to bind the proximal but not the distal CCAAT box.
Roberto Mantovani - One of the best experts on this subject based on the ideXlab platform.
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The phosphorYlatable Ser320 of NF‐YA is involved in DNA binding of the NF‐Y trimer
FASEB journal : official publication of the Federation of American Societies for Experimental Biology, 2018Co-Authors: Andrea Bernardini, Roberto Mantovani, Mariangela Lorenzo, Marco Nardini, Nerina GnesuttaAbstract:Nuclear Factor Y (NF-Y) is a transcription Factor trimer binding to the functionallY important CCAAT box, present in promoters of growth-promoting and cell cYcle-regulated genes. The regulatorY nuc...
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Nuclear Factor Y, Subunit A (NF-YA) Proteins PositivelY Regulate Flowering and Act Through FLOWERING LOCUS T.
PLoS genetics, 2016Co-Authors: Chamindika L. Siriwardana, Roberto Mantovani, Zachary A. Myers, Roderick W. Kumimoto, Nerina Gnesutta, Daniel S. Jones, Ben F. HoltAbstract:Photoperiod dependent flowering is one of several mechanisms used bY plants to initiate the developmental transition from vegetative growth to reproductive growth. The Nuclear Factor Y (NF-Y) transcription Factors are heterotrimeric complexes composed of NF-YA and histone-fold domain (HFD) containing NF-YB/NF-YC, that initiate photoperiod-dependent flowering bY cooperativelY interacting with CONSTANS (CO) to drive the expression of FLOWERING LOCUS T (FT). This involves NF-Y and CO binding at distal CCAAT and proximal “CORE” elements, respectivelY, in the FT promoter. While this is well established for the HFD subunits, there remains some question over the potential role of NF-YA as either positive or negative regulators of this process. Here we provide strong support, in the form of genetic and biochemical analYses, that NF-YA, in complex with NF-YB/NF-YC proteins, can directlY bind the distal CCAAT box in the FT promoter and are positive regulators of flowering in an FT-dependent manner.
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A Distal CCAAT/Nuclear Factor Y Complex Promotes Chromatin Looping at the FLOWERING LOCUS T Promoter and Regulates the Timing of Flowering in Arabidopsis
The Plant cell, 2014Co-Authors: Shuanghe Cao, Roberto Mantovani, Roderick W. Kumimoto, Nerina Gnesutta, Alessandra M. Calogero, Ben F. HoltAbstract:For manY plant species, reproductive success relies on the proper timing of flowering, and photoperiod provides a keY environmental input. Photoperiod-dependent flowering depends on timelY expression of FLOWERING LOCUS T (FT); however, the coordination of various cis-regulatorY elements in the FT promoter is not well understood. Here, we provide evidence that long-distance chromatin loops bring distal enhancer elements into close association with the proximal promoter elements bound bY CONSTANS (CO). AdditionallY, we show that Nuclear Factor Y (NF-Y) binds a CCAAT box in the distal enhancer element and that CCAAT disruption dramaticallY reduces FT promoter activitY. Thus, we propose the recruitment model of photoperiod-dependent flowering where NF-Y complexes, bound at the FT distal enhancer element, help recruit CO to proximal cis-regulatorY elements and initiate the transition to reproductive growth.
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a distal ccaat Nuclear Factor Y complex promotes chromatin looping at the flowering locus t promoter and regulates the timing of flowering in arabidopsis
The Plant Cell, 2014Co-Authors: Shuanghe Cao, Roberto Mantovani, Roderick W. Kumimoto, Nerina Gnesutta, Alessandra M. Calogero, Ben F. HoltAbstract:For manY plant species, reproductive success relies on the proper timing of flowering, and photoperiod provides a keY environmental input. Photoperiod-dependent flowering depends on timelY expression of FLOWERING LOCUS T (FT); however, the coordination of various cis-regulatorY elements in the FT promoter is not well understood. Here, we provide evidence that long-distance chromatin loops bring distal enhancer elements into close association with the proximal promoter elements bound bY CONSTANS (CO). AdditionallY, we show that Nuclear Factor Y (NF-Y) binds a CCAAT box in the distal enhancer element and that CCAAT disruption dramaticallY reduces FT promoter activitY. Thus, we propose the recruitment model of photoperiod-dependent flowering where NF-Y complexes, bound at the FT distal enhancer element, help recruit CO to proximal cis-regulatorY elements and initiate the transition to reproductive growth.
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The Promiscuous Life of Plant Nuclear Factor Y Transcription Factors
The Plant cell, 2012Co-Authors: Katia Petroni, Ben F. Holt, Roderick W. Kumimoto, Nerina Gnesutta, V. Calvenzani, M. Fornari, Chiara Tonelli, Roberto MantovaniAbstract:The CCAAT box is one of the most common cis-elements present in eukarYotic promoters and is bound bY the transcription Factor Nuclear Factor Y (NF-Y). NF-Y is composed of three subunits, NF-YA, NF-YB, and NF-YC. Unlike animals and fungi, plants have significantlY expanded the number of genes encoding NF-Y subunits. We provide a comprehensive classification of NF-Y genes, with a separation of closelY related, but distinct, histone fold domain proteins. We additionallY review recent experiments that have placed NF-Y at the center of manY developmental stress-responsive processes in the plant lineage.
Hidenari Takahara - One of the best experts on this subject based on the ideXlab platform.
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estrogen enhanced peptidYlarginine deiminase tYpe iv gene padi4 expression in mcf 7 cells is mediated bY estrogen receptor α promoted transFactors activator protein 1 Nuclear Factor Y and sp1
Molecular Endocrinology, 2007Co-Authors: Sijun Dong, Zilian Zhang, Hidenari TakaharaAbstract:Human peptidYlarginine deiminase tYpe IV (PAD4), a Ca2+-dependent enzYme known to convert arginine residues to citrulline residues in histones, has been shown to be associated with the development of rheumatoid arthritis. RecentlY, it was noted that the human peptidYlarginine deiminase tYpe IV gene (PADI4) regulates the expression of estrogen-responsive genes bY modifYing the methYlated arginine sites in histones H3 and H4. In this studY, we demonstrated that PADI4 was expressed in MCF-7 cells and was responsive to estrogen at the transcriptional level. Using the luciferase reporter gene fused to wild-tYpe or mutated 5′-flanking region of PADI4, we characterized that as few as 348 bp upstream from the transcription initiation site were sufficient to direct transcription of the reporter gene. Chromatin immunoprecipitation and small interfering RNA assaYs revealed that activator protein–1, Sp1/Sp3, and Nuclear Factor–Y were cis-acting Factors bound to the minimal promoter of PADI4 and that theY regulated ge...
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Estrogen-Enhanced PeptidYlarginine Deiminase TYpe IV Gene (PADI4) Expression in MCF-7 Cells Is Mediated bY Estrogen Receptor-α-Promoted TransFactors Activator Protein-1, Nuclear Factor-Y, and Sp1
Molecular endocrinology (Baltimore Md.), 2007Co-Authors: Sijun Dong, Zilian Zhang, Hidenari TakaharaAbstract:Human peptidYlarginine deiminase tYpe IV (PAD4), a Ca(2+)-dependent enzYme known to convert arginine residues to citrulline residues in histones, has been shown to be associated with the development of rheumatoid arthritis. RecentlY, it was noted that the human peptidYlarginine deiminase tYpe IV gene (PADI4) regulates the expression of estrogen-responsive genes bY modifYing the methYlated arginine sites in histones H3 and H4. In this studY, we demonstrated that PADI4 was expressed in MCF-7 cells and was responsive to estrogen at the transcriptional level. Using the luciferase reporter gene fused to wild-tYpe or mutated 5'-flanking region of PADI4, we characterized that as few as 348 bp upstream from the transcription initiation site were sufficient to direct transcription of the reporter gene. Chromatin immunoprecipitation and small interfering RNA assaYs revealed that activator protein-1, Sp1/Sp3, and Nuclear Factor-Y were cis-acting Factors bound to the minimal promoter of PADI4 and that theY regulated gene expression in a cooperative manner. Moreover, it was indicated that estrogen stimulated PADI4 expression through binding of estrogen receptor (ER)-alpha to the upstream of the PADI4 gene and ERalpha-mediated enhancement of activator protein-1, Sp1, and Nuclear Factor-Y levels. These findings indicated that estrogen stimulated PADI4 expression through both of the classical and nonclassical ER-mediated pathwaYs.
