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Richard C Scarpulla - One of the best experts on this subject based on the ideXlab platform.
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a common set of gene regulatory networks links metabolism and growth inhibition
Molecular Cell, 2004Co-Authors: Hugh Cam, Richard C Scarpulla, Egle Balciunaite, Alexandre Blais, Alexander Spektor, Richard A Young, Yuval Kluger, Brian David DynlachtAbstract:Using genome-wide analysis of transcription Factor occupancy, we investigated the mechanisms underlying three mammalian growth arrest pathways that require the pRB tumor suppressor family. We found that p130 and E2F4 cooperatively repress a common set of genes under each growth arrest condition and showed that growth arrest is achieved through repression of a core set of genes involved not only in cell cycle control but also mitochondrial biogenesis and metabolism. Motif-finding algorithms predicted the existence of Nuclear Respiratory Factor-1 (NRF1) binding sites in E2F target promoters, and genome-wide Factor binding analysis confirmed our predictions. We showed that NRF1, a Factor known to regulate expression of genes involved in mitochondrial function, is a coregulator of a large number of E2F target genes. Our studies provide insights into E2F regulatory circuitry, suggest how Factor occupancy can predict the expression signature of a given target gene, and reveal pathways deregulated in human tumors.
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Nuclear activators and coactivators in mammalian mitochondrial biogenesis
Biochimica et Biophysica Acta, 2002Co-Authors: Richard C ScarpullaAbstract:Abstract The biogenesis of mitochondria requires the expression of a large number of genes, most of which reside in the Nuclear genome. The protein-coding capacity of mtDNA is limited to 13 Respiratory subunits necessitating that Nuclear regulatory Factors play an important role in governing nucleo-mitochondrial interactions. Two classes of Nuclear transcriptional regulators implicated in mitochondrial biogenesis have emerged in recent years. The first includes DNA-binding transcription Factors, typified by Nuclear Respiratory Factor (NRF)-1, NRF-2 and others, that act on known Nuclear genes that specify mitochondrial functions. A second, more recently defined class, includes Nuclear coactivators typified by PGC-1 and related family members (PRC and PGC-1β). These molecules do not bind DNA but rather work through their interactions with DNA-bound transcription Factors to regulate gene expression. An important feature of these coactivators is that their expression is responsive to physiological signals mediating thermogenesis, cell proliferation and gluconeogenesis. Thus, they have the ability to integrate the action of multiple transcription Factors in orchestrating programs of gene expression essential to cellular energetics. The interplay of these Nuclear Factors appears to be a major determinant in regulating the biogenesis of mitochondria.
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sequential serum dependent activation of creb and nrf 1 leads to enhanced mitochondrial respiration through the induction of cytochrome c
Journal of Biological Chemistry, 2000Co-Authors: Ronald P Herzig, Salvatore Scacco, Richard C ScarpullaAbstract:Progression through the cell cycle requires ATP for protein synthesis, cytoskeletal rearrangement, chromatin remodeling, and protein degradation. The mechanisms by which mammalian cells increase Respiratory capacity and ATP production in preparation for cell division are largely unexplored. Here, we demonstrate that serum induction of cytochrome c mRNA and processed protein in quiescent BALB/3T3 fibroblasts is associated with a marked increase in mitochondrial respiration. Cytochrome c was induced in the absence of any increase in citrate synthase activity or in subunit IV of the cytochrome c oxidase complex mRNA or protein, indicating that the enhanced Respiratory rate did not require a general increase in mitochondrial biogenesis or Respiratory chain expression. Transfections with a series of cytochrome c promoter mutants showed that both Nuclear Respiratory Factor 1 (NRF-1) and cAMP-response element-binding protein (CREB) binding sites contributed equally to induced expression by serum. Moreover, CREB and NRF-1 were phosphorylated sequentially in response to serum, and the NRF-1 phosphorylation was accompanied by an increase in its ability to trans-activate target gene expression. The results demonstrate that the differential transcriptional expression of cytochrome c, through sequential transcription Factor phosphorylations, leads to enhanced mitochondrial Respiratory capacity upon serum-induced entry to the cell cycle.
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identity of gabp with nrf 2 a multisubunit activator of cytochrome oxidase expression reveals a cellular role for an ets domain activator of viral promoters
Genes & Development, 1993Co-Authors: Joseph V Virbasius, C M A Virbasius, Richard C ScarpullaAbstract:The ETS domain proteins are a diverse family of transcriptional activators that have been implicated recently in the expression of a number of cell-specific and viral promoters. Nuclear Respiratory Factor 2 (NRF-2) is a Nuclear transcription Factor that activates the proximal promoter of the rat cytochrome c oxidase subunit IV (RCO4) gene through tandem sequence elements. These elements conform to the consensus for high-affinity ETS domain recognition sites. We have now purified NRF-2 to homogeneity from HeLa cells and find that it consists of five polypeptides, only one of which has intrinsic DNA-binding ability. The others participate in the formation of heteromeric complexes with distinct binding properties. NRF-2 also specifically recognizes multiple binding sites in the mouse cytochrome c oxidase subunit Vb (MCO5b) gene. As in the functionally related RCO4 gene, tandemly arranged NRF-2 sites are essential for the activity of the proximal MCO5b promoter, further substantiating a role for NRF-2 in Respiratory chain expression. Determination of peptide sequences from the various subunits of HeLa NRF-2 reveals a high degree of sequence identity with mouse GA-binding protein (GABP), a multisubunit ETS domain activator of herpes simplex virus immediate early genes. A cellular role in the activation of Nuclear genes specifying mitochondrial Respiratory function is thus assigned to an ETS domain activator of viral promoters.
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Nuclear Respiratory Factor 1 activation sites in genes encoding the gamma subunit of atp synthase eukaryotic initiation Factor 2 alpha and tyrosine aminotransferase specific interaction of purified nrf 1 with multiple target genes
Journal of Biological Chemistry, 1992Co-Authors: Ching Man A Chau, Mark J Evans, Richard C ScarpullaAbstract:Abstract Transcription Factor Nuclear Respiratory Factor 1 (NRF-1) was originally identified as an activator of the cytochrome c gene and subsequently found to stimulate transcription through specific sites in other Nuclear genes whose products function in the mitochondria. These include subunits of the cytochrome oxidase and reductase complexes and a component of the mitochondrial DNA replication machinery. Here we establish that a functional recognition site for NRF-1 is present in the ATP synthase gamma-subunit gene extending the proposed Respiratory role of NRF-1 to complex V. In addition, biologically active NRF-1 sites are found in genes encoding the eukaryotic translation initiation Factor 2 alpha-subunit and tyrosine aminotransferase, both of which participate in the rate-limiting step of their respective pathways of protein biosynthesis and tyrosine catabolism. The recognition sites from each of these genes form identical complexes with NRF-1 as established by competition binding assays, methylation interference footprinting, and UV-induced DNA cross-linking. Cloned oligomers of each NRF-1 binding site also stimulate the activity of a truncated cytochrome c promoter in transfected cells. The NRF-1 binding activities for the various target sites copurified approximately 33,000-fold and resided in a single protein of 68 kDa. These observations further support a role for NRF-1 in the expression of Nuclear Respiratory genes and suggest it may help coordinate Respiratory metabolism with other biosynthetic and degradative pathways.
Margaret T T Wongriley - One of the best experts on this subject based on the ideXlab platform.
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regulation of na k atpase by Nuclear Respiratory Factor 1 implication in the tight coupling of neuronal activity energy generation and energy consumption
Journal of Biological Chemistry, 2012Co-Authors: Kaid Johar, Anusha Priya, Margaret T T WongrileyAbstract:Energy generation and energy consumption are tightly coupled to neuronal activity at the cellular level. Na+/K+-ATPase, a major energy-consuming enzyme, is well expressed in neurons rich in cytochrome c oxidase, an important enzyme of the energy-generating machinery, and glutamatergic receptors that are mediators of neuronal activity. The present study sought to test our hypothesis that the coupling extends to the molecular level, whereby Na+/K+-ATPase subunits are regulated by the same transcription Factor, Nuclear Respiratory Factor 1 (NRF-1), found recently by our laboratory to regulate all cytochrome c oxidase subunit genes and some NMDA and AMPA receptor subunit genes. By means of multiple approaches, including in silico analysis, electrophoretic mobility shift and supershift assays, in vivo chromatin immunoprecipitation, promoter mutational analysis, and real-time quantitative PCR, NRF-1 was found to functionally bind to the promoters of Atp1a1 and Atp1b1 genes but not of the Atp1a3 gene in neurons. The transcripts of Atp1a1 and Atp1b1 subunit genes were up-regulated by KCl and down-regulated by tetrodotoxin. Atp1b1 is positively regulated by NRF-1, and silencing of NRF-1 with small interference RNA blocked the up-regulation of Atp1b1 induced by KCl, whereas overexpression of NRF-1 rescued these transcripts from being suppressed by tetrodotoxin. On the other hand, Atp1a1 is negatively regulated by NRF-1. The binding sites of NRF-1 on Atp1a1 and Atp1b1 are conserved among mice, rats, and humans. Thus, NRF-1 regulates key Na+/K+-ATPase subunits and plays an important role in mediating the tight coupling between energy consumption, energy generation, and neuronal activity at the molecular level.
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chromosome conformation capture of transcriptional interactions between cytochrome c oxidase genes and genes of glutamatergic synaptic transmission in neurons
Journal of Neurochemistry, 2010Co-Authors: Shilpa S. Dhar, Margaret T T WongrileyAbstract:J. Neurochem. (2010) 115, 676–683. Abstract Neuronal activity and energy metabolism are tightly coupled processes. Recently, we found that Nuclear Respiratory Factor 1 co-regulates all subunits of cytochrome c oxidase (COX, representing oxidative energy metabolism) and glutamatergic neurochemicals, including NR1 (Grin1) and NR2B (Grin2b) of NMDA receptors, GluR2 (Gria2) of alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptors, and neuronal nitric oxide synthase (Nos1). Moreover, all 10 Nuclear-encoded COX subunit genes and three transcription Factor genes for the three mitochondrial-encoded COX subunits are transcribed in the same transcription Factory. The goal of the present study was to test our hypothesis that genomic loci for Grin1, Grin2b, Gria2, and Nos1 interact with those for COX at the transcriptional level. By means of chromosome conformation capture, interactions were found among all of these genes in neurons, but not in C2C12 muscle cells. COX subunit genes also did not interact with neurochemical genes not regulated by Nuclear Respiratory Factor 1, nor with genes for calreticulin, a non-mitochondrial protein. Depolarizing stimulation up-regulated interaction frequencies between COX and neurochemical genes, whereas impulse blockade with tetrodotoxin or inhibition of COX with KCN down-regulated them in neurons. Thus, an efficient mechanism is in place for coordinating the transcriptional coupling of energy metabolism and glutamatergic neurotransmission at the molecular level in neurons.
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Nuclear Respiratory Factor 1 co regulates ampa glutamate receptor subunit 2 and cytochrome c oxidase tight coupling of glutamatergic transmission and energy metabolism in neurons
Journal of Neurochemistry, 2009Co-Authors: Shilpa S. Dhar, Huan Ling Liang, Margaret T T WongrileyAbstract:Neuronal activity, especially of the excitatory glutamatergic type, is highly dependent on energy from the oxidative pathway. We hypothesized that the coupling existed at the transcriptional level by having the same transcription Factor to regulate a marker of energy metabolism, cytochrome c oxidase (COX) and an important subunit of alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid glutamate receptors, GluR2 (Gria2). Nuclear Respiratory Factor 1 (NRF-1) was a viable candidate because it regulates all COX subunits and potentially activates Gria2. By means of in silico analysis, electrophoretic mobility shift and supershift, chromatin immunoprecipitation, and promoter mutational assays, we found that NRF-1 functionally bound to Gria2 promoter. Silencing of NRF-1 with small interference RNA prevented the depolarization-stimulated up-regulation of Gria2 and COX, and over-expression of NRF-1 rescued neurons from tetrodotoxin-induced down-regulation of Gria2 and COX transcripts. Thus, neuronal activity and energy metabolism are tightly coupled at the molecular level, and NRF-1 is a critical agent in this process.
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human Nuclear Respiratory Factor 2 subunit cdna isolation subcloning sequencing and in situ hybridization of transcripts in normal and monocularly deprived macaque visual system
The Journal of Comparative Neurology, 2000Co-Authors: Aili Guo, Feng Nie, Margaret T T WongrileyAbstract:Nuclear Respiratory Factor 2 (NRF-2) has been shown to contribute to the transcriptional regulation of a number of subunits of Respiratory chain enzymes, including cytochrome c oxidase (CO). Our recent study demonstrated a parallel distribution of the alpha subunit proteins of NRF-2 (NRF-2 alpha) with CO in the monkey striate cortex, and that it can be regulated by neuronal activity. To determine whether this regulation is at the transcriptional level, the present study examined the expression of NRF-2 alpha mRNA in normal and monocularly deprived adult monkeys. A partial NRF-2 alpha cDNA was isolated from a human brain cDNA library. Sequence analysis revealed that it shared 99% identity with the published sequence from human HeLa cells. Riboprobes of NRF-2 alpha was generated and labeled with digoxigenin-11-UTP for in situ hybridization. The expression pattern of NRF-2 alpha mRNA in the normal striate cortex paralleled that of CO activity. It was highly expressed in layers IVC and VI, which contained high levels of CO, and more densely expressed in puffs of layers II and III than in interpuffs. In monkeys monocularly treated with tetrodotoxin for 1 day to 2 weeks, both NRF-2 alpha expression and CO activity were reduced in deprived ocular dominance columns of the visual cortex and in deprived layers of the lateral geniculate nucleus. These data indicate that, in the normal and visually deprived adult monkeys, NRF-2 alpha is regulated by neuronal activity at the transcriptional level.
Hagir B Suliman - One of the best experts on this subject based on the ideXlab platform.
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Molecular Medicine Heme Oxygenase-1 Regulates Cardiac Mitochondrial Biogenesis via Nrf2-Mediated Transcriptional Control of Nuclear Respiratory Factor-1
2016Co-Authors: Claude A Piantadosi, Martha Sue Carraway, Abdelwahid Babiker, Hagir B SulimanAbstract:Abstract—Heme oxygenase (HO)-1 is a protective antioxidant enzyme that prevents cardiomyocyte apoptosis, for instance, during progressive cardiomyopathy. Here we identify a fundamental aspect of the HO-1 protection mechanism by demonstrating that HO-1 activity in mouse heart stimulates the bigenomic mitochondrial biogenesis program via induction of NF-E2–related Factor (Nrf)2 gene expression and Nuclear translocation. Nrf2 upregulates the mRNA, protein, and activity for HO-1 as well as mRNA and protein for Nuclear Respiratory Factor (NRF)-1. Mechanistically, in cardiomyocytes, endogenous carbon monoxide (CO) generated by HO-1 overexpression stimulates superoxide dismutase-2 upregulation and mitochondrial H2O2 production, which activates Akt/PKB. Akt deactivates glycogen synthase kinase-3, which permits Nrf2 Nuclear translocation and occupancy of 4 antioxidant response elements (AREs) in the NRF-1 promoter. The ensuing accumulation of Nuclear NRF-1 protein leads to gene activation for mitochondrial biogenesis, which opposes apoptosis and necrosis caused by the cardio-toxic anthracycline chemotherapeutic agent, doxorubicin. In cardiac cells, Akt silencing exacerbates doxorubicin-induced apoptosis, and in vivo CO rescues wild-type but not Akt1/ mice from doxorubicin cardiomyopathy. These findings consign HO-1/CO signaling through Nrf2 and Akt to the myocardial transcriptional program for mitochondrial biogenesis, provide a rationale for targeted mitochondrial CO therapy, and connect cardiac mitochondrial volume expansion with the inducible network of xenobiotic and antioxidant cellular defenses. (Circ Res. 2008;103:1232-1240.
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heme oxygenase 1 regulates cardiac mitochondrial biogenesis via nrf2 mediated transcriptional control of Nuclear Respiratory Factor 1
Circulation Research, 2008Co-Authors: Claude A Piantadosi, Martha Sue Carraway, Abdelwahid Babiker, Hagir B SulimanAbstract:Heme oxygenase (HO)-1 is a protective antioxidant enzyme that prevents cardiomyocyte apoptosis, for instance, during progressive cardiomyopathy. Here we identify a fundamental aspect of the HO-1 pr...
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heme oxygenase 1 regulates cardiac mitochondrial biogenesis via nrf2 mediated transcriptional control of Nuclear Respiratory Factor 1
Circulation Research, 2008Co-Authors: Claude A Piantadosi, Martha Sue Carraway, Abdelwahid Babiker, Hagir B SulimanAbstract:Heme oxygenase (HO)-1 is a protective antioxidant enzyme that prevents cardiomyocyte apoptosis, for instance, during progressive cardiomyopathy. Here we identify a fundamental aspect of the HO-1 protection mechanism by demonstrating that HO-1 activity in mouse heart stimulates the bigenomic mitochondrial biogenesis program via induction of NF-E2–related Factor (Nrf)2 gene expression and Nuclear translocation. Nrf2 upregulates the mRNA, protein, and activity for HO-1 as well as mRNA and protein for Nuclear Respiratory Factor (NRF)-1. Mechanistically, in cardiomyocytes, endogenous carbon monoxide (CO) generated by HO-1 overexpression stimulates superoxide dismutase-2 upregulation and mitochondrial H 2 O 2 production, which activates Akt/PKB. Akt deactivates glycogen synthase kinase-3β, which permits Nrf2 Nuclear translocation and occupancy of 4 antioxidant response elements (AREs) in the NRF-1 promoter. The ensuing accumulation of Nuclear NRF-1 protein leads to gene activation for mitochondrial biogenesis, which opposes apoptosis and necrosis caused by the cardio-toxic anthracycline chemotherapeutic agent, doxorubicin. In cardiac cells, Akt silencing exacerbates doxorubicin-induced apoptosis, and in vivo CO rescues wild-type but not Akt1 −/− mice from doxorubicin cardiomyopathy. These findings consign HO-1/CO signaling through Nrf2 and Akt to the myocardial transcriptional program for mitochondrial biogenesis, provide a rationale for targeted mitochondrial CO therapy, and connect cardiac mitochondrial volume expansion with the inducible network of xenobiotic and antioxidant cellular defenses.
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transcriptional regulation of sdha flavoprotein by Nuclear Respiratory Factor 1 prevents pseudo hypoxia in aerobic cardiac cells
Journal of Biological Chemistry, 2008Co-Authors: Claude A Piantadosi, Hagir B SulimanAbstract:Nuclear Respiratory Factor-1 (NRF-1) is integral to the transcriptional regulation of mitochondrial biogenesis, but its control over various Respiratory genes overlaps other regulatory elements including those involved in O2 sensing. Aerobic metabolism generally suppresses hypoxia-sensitive genes, e.g. via hypoxia-inducible Factor-1 (HIF-1), but mutations in Complex II-succinate dehydrogenase (SDH), a tumor suppressor, stabilize HIF-1, producing pseudo-hypoxia. In aerobic cardiomyocytes, which rely on oxidative phosphorylation, we tested the hypothesis that NRF-1 regulates Complex II expression and opposes hypoxia-inducible Factor-1. NRF-1 gene silencing blocked aerobic succinate oxidation, increasing Nuclear HIF-1α protein prior to the loss of Complex I function. We postulated that NRF-1 suppression either specifically decreases the expression of one or more SDH subunits and increases succinate availability to regulate HIF-1 prolyl hydroxylases, or stimulates mitochondrial reactive oxygen production, which interferes with HIF-1α degradation. Using promoter analysis, gene silencing, and chromatin immunoprecipitation, NRF-1 was found to bind to the gene promoters of two of four Nuclear-encoded Complex II subunits: SDHa and SDHd, but the enzyme activity was dynamically regulated through the catalytic SDHa flavoprotein. Complex II was inactivated by SDHa silencing, which led to aerobic HIF-1α stabilization, Nuclear translocation, and enhanced expression of glucose transporters and heme oxygenase-1. This was unrelated to mitochondrial ROS production, reversible by high α-ketoglutarate concentrations, and coherent with regulation of HIF-1 by succinate reported in tumor cells. These findings disclose a novel role for NRF-1 in the transcriptional control of Complex II and prevention of pseudo-hypoxic gene expression in aerobic cardiac cells.
Margaret T.t. Wong-riley - One of the best experts on this subject based on the ideXlab platform.
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Nuclear Respiratory Factor 2 regulates the transcription of AMPA receptor subunit GluA2 (Gria2).
Biochimica et biophysica acta, 2014Co-Authors: Anusha Priya, Kaid Johar, Bindu Nair, Margaret T.t. Wong-rileyAbstract:Neuronal activity is highly dependent on energy metabolism. Nuclear Respiratory Factor 2 (NRF-2) tightly couples neuronal activity and energy metabolism by transcriptionally co-regulating all 13 subunits of an important energy-generating enzyme, cytochrome c oxidase (COX), as well as critical subunits of excitatory NMDA receptors. AMPA receptors are another major class of excitatory glutamatergic receptors that mediate most of the fast excitatory synaptic transmission in the brain. They are heterotetrameric proteins composed of various combinations of GluA1-4 subunits, with GluA2 being the most common one. We have previously shown that GluA2 (Gria2) is transcriptionally regulated by Nuclear Respiratory Factor 1 (NRF-1) and specificity protein 4 (Sp4), which also regulate all subunits of COX. However, it was not known if NRF-2 also couples neuronal activity and energy metabolism by regulating subunits of the AMPA receptors. By means of multiple approaches, including electrophoretic mobility shift and supershift assays, chromatin immunoprecipitation, promoter mutations, real-time quantitative PCR, and western blot analysis, NRF-2 was found to functionally regulate the expression of Gria2, but not of Gria1, Gria3, or Gria4 genes in neurons. By regulating the GluA2 subunit of the AMPA receptor, NRF-2 couples energy metabolism and neuronal activity at the transcriptional level through a concurrent and parallel mechanism with NRF-1 and Sp4.
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Specificity protein 4 (Sp4) regulates the transcription of AMPA receptor subunit GluA2 (Gria2).
Biochimica et biophysica acta, 2014Co-Authors: Anusha Priya, Kaid Johar, Bindu Nair, Margaret T.t. Wong-rileyAbstract:The alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptors are important glutamatergic receptors mediating fast excitatory synaptic transmission in the brain. The regulation of the four subunits of AMPA receptors, GluA1-4, is poorly understood. Excitatory synaptic transmission is highly energy-demanding, and this energy is derived mainly from the oxidative pathway. Recently, we found that specificity Factor regulates all subunits of cytochrome c oxidase (COX), a critical energy-generating enzyme. COX is also regulated by Nuclear Respiratory Factor 1 (NRF-1), which transcriptionally controls the Gria2 (GluA2) gene of AMPA receptors. The goal of the present study was to test our hypothesis that Sp-Factors (Sp1, Sp3, and/or Sp4) also regulate AMPA subunit genes. If so, we wish to determine if Sp-Factors and NRF-1 function via a complementary, concurrent and parallel, or a combination of complementary and concurrent/parallel mechanism. By means of multiple approaches, including electrophoretic mobility shift and supershift assays, chromatin immunoprecipitation, promoter mutations, real-time quantitative PCR, and western blot analysis, we found that Sp4, but not Sp1 or Sp3, regulates the Gria2, but not Gria1, 3, or 4, subunit gene of the AMPA receptor in a concurrent and parallel manner with NRF-1. Thus, Sp4 and NRF-1 both mediate the tight coupling between neuronal activity and energy metabolism at the transcriptional level.
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Nuclear Respiratory Factor 2 regulates the expression of the same NMDA receptor subunit genes as NRF-1: Both Factors act by a concurrent and parallel mechanism to couple energy metabolism and synaptic transmission
Biochimica et biophysica acta, 2012Co-Authors: Anusha Priya, Kaid Johar, Margaret T.t. Wong-rileyAbstract:Neuronal activity and energy metabolism are tightly coupled processes. Previously, we found that Nuclear Respiratory Factor 1 (NRF-1) transcriptionally co-regulates energy metabolism and neuronal activity by regulating all 13 subunits of the critical energy generating enzyme, cytochrome c oxidase (COX), as well as N-methyl-d-aspartate (NMDA) receptor subunits 1 and 2B, GluN1 (Grin1) and GluN2B (Grin2b). We also found that another transcription Factor, Nuclear Respiratory Factor 2 (NRF-2 or GA-binding protein) regulates all subunits of COX as well. The goal of the present study was to test our hypothesis that NRF-2 also regulates specific subunits of NMDA receptors, and that it functions with NRF-1 via one of three mechanisms: complementary, concurrent and parallel, or a combination of complementary and concurrent/parallel. By means of multiple approaches, including in silico analysis, electrophoretic mobility shift and supershift assays, in vivo chromatin immunoprecipitation of mouse neuroblastoma cells and rat visual cortical tissue, promoter mutations, real-time quantitative PCR, and western blot analysis, NRF-2 was found to functionally regulate Grin1 and Grin2b genes, but not any other NMDA subunit genes. Grin1 and Grin2b transcripts were up-regulated by depolarizing KCl, but silencing of NRF-2 prevented this up-regulation. On the other hand, over-expression of NRF-2 rescued the down-regulation of these subunits by the impulse blocker TTX. NRF-2 binding sites on Grin1 and Grin2b are conserved among species. Our data indicate that NRF-2 and NRF-1 operate in a concurrent and parallel manner in mediating the tight coupling between energy metabolism and neuronal activity at the molecular level.
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Coupling of Energy Metabolism and Synaptic Transmission at the Transcriptional Level: Role of Nuclear Respiratory Factor 1 in Regulating both Cytochrome c Oxidase and NMDA Glutamate Receptor Subunit Genes
The Journal of neuroscience : the official journal of the Society for Neuroscience, 2009Co-Authors: Shilpa S. Dhar, Margaret T.t. Wong-rileyAbstract:Neuronal activity and energy metabolism are tightly coupled processes. Regions high in neuronal activity, especially of the glutamatergic type, have high levels of cytochrome c oxidase (COX). Perturbations in neuronal activity affect the expressions of COX and glutamatergic NMDA receptor subunit 1 (NR1). The present study sought to test our hypothesis that the coupling extends to the transcriptional level, whereby NR1 and possibly other NR subunits and COX are coregulated by the same transcription Factor, Nuclear Respiratory Factor 1 (NRF-1), which regulates all COX subunit genes. By means of multiple approaches, including in silico analysis, electrophoretic mobility shift and supershift assays, in vivo chromatin immunoprecipitation, promoter mutations, and real-time quantitative PCR, NRF-1 was found to functionally bind to the promoters of Grin 1 (NR1), Grin 2b (NR2b) and COX subunit genes, but not of Grin2a and Grin3a genes. These transcripts were upregulated by KCl and downregulated by tetrodotoxin (TTX) in cultured primary neurons. However, silencing of NRF-1 with small interference RNA blocked the upregulation of Grin1, Grin2b, and COX induced by KCl, and overexpression of NRF-1 rescued these transcripts that were suppressed by TTX. NRF-1 binding sites on Grin1 and Grin2b genes are also highly conserved among mice, rats, and humans. Thus, NRF-1 is an essential transcription Factor critical in the coregulation of NR1, NR2b, and COX, and coupling exists at the transcriptional level to ensure coordinated expressions of proteins important for synaptic transmission and energy metabolism.
Anusha Priya - One of the best experts on this subject based on the ideXlab platform.
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Nuclear Respiratory Factor 2 regulates the transcription of AMPA receptor subunit GluA2 (Gria2).
Biochimica et biophysica acta, 2014Co-Authors: Anusha Priya, Kaid Johar, Bindu Nair, Margaret T.t. Wong-rileyAbstract:Neuronal activity is highly dependent on energy metabolism. Nuclear Respiratory Factor 2 (NRF-2) tightly couples neuronal activity and energy metabolism by transcriptionally co-regulating all 13 subunits of an important energy-generating enzyme, cytochrome c oxidase (COX), as well as critical subunits of excitatory NMDA receptors. AMPA receptors are another major class of excitatory glutamatergic receptors that mediate most of the fast excitatory synaptic transmission in the brain. They are heterotetrameric proteins composed of various combinations of GluA1-4 subunits, with GluA2 being the most common one. We have previously shown that GluA2 (Gria2) is transcriptionally regulated by Nuclear Respiratory Factor 1 (NRF-1) and specificity protein 4 (Sp4), which also regulate all subunits of COX. However, it was not known if NRF-2 also couples neuronal activity and energy metabolism by regulating subunits of the AMPA receptors. By means of multiple approaches, including electrophoretic mobility shift and supershift assays, chromatin immunoprecipitation, promoter mutations, real-time quantitative PCR, and western blot analysis, NRF-2 was found to functionally regulate the expression of Gria2, but not of Gria1, Gria3, or Gria4 genes in neurons. By regulating the GluA2 subunit of the AMPA receptor, NRF-2 couples energy metabolism and neuronal activity at the transcriptional level through a concurrent and parallel mechanism with NRF-1 and Sp4.
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Specificity protein 4 (Sp4) regulates the transcription of AMPA receptor subunit GluA2 (Gria2).
Biochimica et biophysica acta, 2014Co-Authors: Anusha Priya, Kaid Johar, Bindu Nair, Margaret T.t. Wong-rileyAbstract:The alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptors are important glutamatergic receptors mediating fast excitatory synaptic transmission in the brain. The regulation of the four subunits of AMPA receptors, GluA1-4, is poorly understood. Excitatory synaptic transmission is highly energy-demanding, and this energy is derived mainly from the oxidative pathway. Recently, we found that specificity Factor regulates all subunits of cytochrome c oxidase (COX), a critical energy-generating enzyme. COX is also regulated by Nuclear Respiratory Factor 1 (NRF-1), which transcriptionally controls the Gria2 (GluA2) gene of AMPA receptors. The goal of the present study was to test our hypothesis that Sp-Factors (Sp1, Sp3, and/or Sp4) also regulate AMPA subunit genes. If so, we wish to determine if Sp-Factors and NRF-1 function via a complementary, concurrent and parallel, or a combination of complementary and concurrent/parallel mechanism. By means of multiple approaches, including electrophoretic mobility shift and supershift assays, chromatin immunoprecipitation, promoter mutations, real-time quantitative PCR, and western blot analysis, we found that Sp4, but not Sp1 or Sp3, regulates the Gria2, but not Gria1, 3, or 4, subunit gene of the AMPA receptor in a concurrent and parallel manner with NRF-1. Thus, Sp4 and NRF-1 both mediate the tight coupling between neuronal activity and energy metabolism at the transcriptional level.
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regulation of na k atpase by Nuclear Respiratory Factor 1 implication in the tight coupling of neuronal activity energy generation and energy consumption
Journal of Biological Chemistry, 2012Co-Authors: Kaid Johar, Anusha Priya, Margaret T T WongrileyAbstract:Energy generation and energy consumption are tightly coupled to neuronal activity at the cellular level. Na+/K+-ATPase, a major energy-consuming enzyme, is well expressed in neurons rich in cytochrome c oxidase, an important enzyme of the energy-generating machinery, and glutamatergic receptors that are mediators of neuronal activity. The present study sought to test our hypothesis that the coupling extends to the molecular level, whereby Na+/K+-ATPase subunits are regulated by the same transcription Factor, Nuclear Respiratory Factor 1 (NRF-1), found recently by our laboratory to regulate all cytochrome c oxidase subunit genes and some NMDA and AMPA receptor subunit genes. By means of multiple approaches, including in silico analysis, electrophoretic mobility shift and supershift assays, in vivo chromatin immunoprecipitation, promoter mutational analysis, and real-time quantitative PCR, NRF-1 was found to functionally bind to the promoters of Atp1a1 and Atp1b1 genes but not of the Atp1a3 gene in neurons. The transcripts of Atp1a1 and Atp1b1 subunit genes were up-regulated by KCl and down-regulated by tetrodotoxin. Atp1b1 is positively regulated by NRF-1, and silencing of NRF-1 with small interference RNA blocked the up-regulation of Atp1b1 induced by KCl, whereas overexpression of NRF-1 rescued these transcripts from being suppressed by tetrodotoxin. On the other hand, Atp1a1 is negatively regulated by NRF-1. The binding sites of NRF-1 on Atp1a1 and Atp1b1 are conserved among mice, rats, and humans. Thus, NRF-1 regulates key Na+/K+-ATPase subunits and plays an important role in mediating the tight coupling between energy consumption, energy generation, and neuronal activity at the molecular level.
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Nuclear Respiratory Factor 2 regulates the expression of the same NMDA receptor subunit genes as NRF-1: Both Factors act by a concurrent and parallel mechanism to couple energy metabolism and synaptic transmission
Biochimica et biophysica acta, 2012Co-Authors: Anusha Priya, Kaid Johar, Margaret T.t. Wong-rileyAbstract:Neuronal activity and energy metabolism are tightly coupled processes. Previously, we found that Nuclear Respiratory Factor 1 (NRF-1) transcriptionally co-regulates energy metabolism and neuronal activity by regulating all 13 subunits of the critical energy generating enzyme, cytochrome c oxidase (COX), as well as N-methyl-d-aspartate (NMDA) receptor subunits 1 and 2B, GluN1 (Grin1) and GluN2B (Grin2b). We also found that another transcription Factor, Nuclear Respiratory Factor 2 (NRF-2 or GA-binding protein) regulates all subunits of COX as well. The goal of the present study was to test our hypothesis that NRF-2 also regulates specific subunits of NMDA receptors, and that it functions with NRF-1 via one of three mechanisms: complementary, concurrent and parallel, or a combination of complementary and concurrent/parallel. By means of multiple approaches, including in silico analysis, electrophoretic mobility shift and supershift assays, in vivo chromatin immunoprecipitation of mouse neuroblastoma cells and rat visual cortical tissue, promoter mutations, real-time quantitative PCR, and western blot analysis, NRF-2 was found to functionally regulate Grin1 and Grin2b genes, but not any other NMDA subunit genes. Grin1 and Grin2b transcripts were up-regulated by depolarizing KCl, but silencing of NRF-2 prevented this up-regulation. On the other hand, over-expression of NRF-2 rescued the down-regulation of these subunits by the impulse blocker TTX. NRF-2 binding sites on Grin1 and Grin2b are conserved among species. Our data indicate that NRF-2 and NRF-1 operate in a concurrent and parallel manner in mediating the tight coupling between energy metabolism and neuronal activity at the molecular level.
