Sequences required for in vitro transcriptional activation of a Drosophila hsp 70 gene

Topol, Joanne; Ruden, Douglas M.; Parker, Carl S.

doi:10.1016/0092-8674(85)90110-2

Cited by 288 publications

(186 citation statements)

References 18 publications

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“…Regulation of gene expression through the cooperative interaction of DNA-binding proteins also has been ob served with mammalian proteins (Topol et al 1985;Da vidson et al 1988;Tsai et al 1989). The ability of Oct-2 molecules to interact cooperatively when binding to oc tamer sites may account for the observed synergistic transcriptional activity of the immunoglobulin heavychain promoter and enhancer (Garcia et al 1986).…”

Section: Discussionmentioning

confidence: 99%

The Oct-2 protein binds cooperatively to adjacent octamer sites.

et al. 1989

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Recombinant proteins derived from the cloned human oct-2 gene were used to investigate cooperative binding by Oct-2 to adjacent DNA-binding sites. Oct-2, a B-cell-specific transcription factor, binds tightly to the octamer sequence in immunoglobulin promoters. A second apparently unrelated consensus sequence in heavy chain promoters, the heptamer site, also is recognized by the Oct-2 protein but with 1000-fold lower affinity. Simultaneous occupancy of both the octamer and heptamer sites is favored by cooperative interactions. The heptamer site is probably recognized by the same binding surface in the Oct-2 protein as the octamer site and thus is conserved as a lower-affinity binding site. This permits the immunoglobulin promoter to respond to a much broader range of levels of Oct-2 protein. Substitution of prototype octamer sequences for heptamer sequences yields a probe with two octamer sites spaced by 2 nucleotides, which also binds Oct-2 protein cooperatively. Only the POU domain in the Oct-2 protein is required for this cooperative interaction. Similar protein-protein interactions between bound Oct-2 proteins may promote promoter-enhancer synergism in the heavy chain gene.

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Section: Discussionmentioning

confidence: 99%

The Oct-2 protein binds cooperatively to adjacent octamer sites.

et al. 1989

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“…The binding of HSF-1 to HSE occurs at −192 in the HSP70 promoter relative to the transcription initiation site. The EMF domain contains three nCTCTn myc-binding sites −230, −166 and −160 relative to the transcription initiation site and upstream of the binding sites for the heat shock (nGAAn) and serum responsive elements [5,6,17,18]. The electromagnetic response elements (EMREs) have also been identified on the c-myc promoter and are also responsive to EMF.…”

Section: Physiological Stress and Cellular Stressmentioning

confidence: 99%

Electromagnetic fields stress living cells

2009

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Electromagnetic fields (EMF), in both ELF (extremely low frequency) and radio frequency (RF) ranges, activate the cellular stress response, a protective mechanism that induces the expression of stress response genes, e.g., HSP70, and increased levels of stress proteins, e.g., hsp70. The 20 different stress protein families are evolutionarily conserved and act as 'chaperones' in the cell when they 'help' repair and refold damaged proteins and transport them across cell membranes. Induction of the stress response involves activation of DNA, and despite the large difference in energy between ELF and RF, the same cellular pathways respond in both frequency ranges. Specific DNA sequences on the promoter of the HSP70 stress gene are responsive to EMF, and studies with model biochemical systems suggest that EMF could interact directly with electrons in DNA. While low energy EMF interacts with DNA to induce the stress response, increasing EMF energy in the RF range can lead to breaks in DNA strands. It is clear that in order to protect living cells, EMF safety limits must be changed from the current thermal standard, based on energy, to one based on biological responses that occur long before the threshold for thermal changes. © 2009 Elsevier Ireland Ltd. All rights reserved.Keywords: DNA; Biosynthesis; Electromagnetic fields; ELF; RF Electromagnetic fields (EMF) alter protein synthesisUntil recently, genetic information stored in DNA was considered essentially invulnerable to change as it was passed on from parent to progeny. Mutations, such as those caused by cosmic radiation at the most energetic end of the EM spectrum, were thought to be relatively infrequent. The model of gene regulation was believed to be that the negatively charged DNA was tightly wrapped up in the nucleus with positively charged histones, and that most genes were 'turned off' most of the time. Of course, different regions of the DNA code are being read more or less all the time to replenish essential Abbreviations: EMF, electromagnetic fields; Hz, hertz; ELF, extremely low frequency; RF, radio frequency; MAPK, mitogen activated protein kinase; ERK1\2, extracellular signal regulated kinase; JNK, c-Jun-terminal kinase p38MAPK; SAPK, stress activated protein kinase; NADH, nicotinamide adenine dinucleotide dehydrogenase; ROS, reactive oxygen species.* Corresponding author at: Department of Physiology, Columbia Univer- proteins that have broken down and those needed during cell division. New insights into the structure and function of DNA have resulted from numerous, well-done laboratory studies. The demonstration that EMF induces gene expression and the synthesis of specific proteins [1,2] generated considerable controversy from power companies, government agencies, physicists, and most recently, cell phone companies. Physicists have insisted that the reported results were not possible because there was not enough energy in the power frequency range (ELF) to activate DNA. They were thinking solely of mechanical interaction with a large molec...

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“…In particular, the study of proteins which bind sequence specifically to promoter and enhancer elements and to viral origins of DNA replication has received much attention recently (Dynan and Tjian, 1985;Serfling et al, 1985;McKnight and Tjian, 1986;Kadonaga et al, 1986;StilUman et al, 1985;Rawlins et al, 1985;Pruijn et al, 1986a;Rosenfeld et al, 1987). In vitro and in vivo studies have shown that binding sites for these proteins are important elements in the regulation of transcription of the linked genes and in the initiation of DNA replication at the linked origins respectively (Lebowitz and Ghosh, 1982;Topol et al, 1985;Kadonaga et al, 1986;McKnight and Tjian, 1986;Stillman et al, 1985;Rawlins et al, 1985;Leegwater et al, 1985;De Vries et al, 1985;Hay, 1985a;Pruijn et al, 1986a;Rosenfeld et al, 1987).…”

Section: Introductionmentioning

confidence: 99%

Promoter and enhancer elements containing a conserved sequence motif are recognized by nuclear factor III, a protein stimulating adenovirus DNA replication.

et al. 1987

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Nuclear factor HI (NFI) is a protein from HeLa cells that stimulates the initiation of adenovirus type 2 (Ad2) DNA replication by binding to a specific nucleotide sequence in the orign, adjacent to the nuclear factor I recognition site. DNA sequences sharing a high degree of homology to the NFm binding site in Ad2 were found in a number of transcription regulatory elements, all containing the octanucleotide sequence ATGCAAAT. We have analysed the interaction between NF[II and the octamer-containing sequences in a histone H2B promoter, immunoglobulin light and heavy chain promoters, an immunoglobulin heavy chain enhancer, a U2 snRNA enhancer and the SV40 enhancer as well as Ad4. All sequences were recognized by NlI as indicated by gel retardation assays, DNase I footprinting and methylation protection experiments. A comparison of the relative binding affinities using competition assays indicated that mutations in the octanucleotide sequence reduced the binding affinity considerably. Small but signifit differences in affinity were also observed depending on the sequences bordering the conserved octanucleotide. The methylation protection patterns indicate that both major and minor groove contacts are involved in NFIII binding. The data suggest that NFEL could function both in adenovirus DNA replication and in the transcriptional control of several groups of genes sharing the octanucleotide sequence.

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Sequences required for in vitro transcriptional activation of a Drosophila hsp 70 gene

Cited by 288 publications

References 18 publications

The Oct-2 protein binds cooperatively to adjacent octamer sites.

The Oct-2 protein binds cooperatively to adjacent octamer sites.

Electromagnetic fields stress living cells

Promoter and enhancer elements containing a conserved sequence motif are recognized by nuclear factor III, a protein stimulating adenovirus DNA replication.

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