Nuclear activity from F9 embryonal carcinoma cells binding specifically to the enhancers of wild-type polyoma virus and PyEC mutant DNAs

Fujimura, Frank K.

doi:10.1093/nar/14.7.2845

Cited by 49 publications

(42 citation statements)

References 63 publications

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“…Base substitution mutations in the P (B) element result in their ability to allow Py to replicate in the mouse embryonal carcinoma cell line F9 (see reference 1 and references therein), presumably owing to increased enhancer function. DNase I-hypersensitive sites are located in both a (A) and P (B) regions (7,27), and nuclear proteins capable of binding to sites within the enhancer have been described (6,20,41,43). It has been speculated that the binding of specific proteins to the enhancer region modifies the interaction of the core ori with the replication complex (16).…”

Section: Discussionmentioning

confidence: 99%

DNA sequence requirements for replication of polyomavirus DNA in vivo and in vitro.

Prives¹,

Murakami²,

Kern³

et al. 1987

Mol. Cell. Biol.

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Cell extracts of FM3A mouse cells replicate polyomavirus (Py) DNA in the presence of immunoaffinitypurified Py large T antigen, deoxynucleoside triphosphates, ATP, and an ATP-generating system. This system was used to examine the effects of mutations within or adjacent to the Py core origin (on) region in vitro. The analysis of plasmid DNAs containing deletions within the early-gene side of the Py core ori indicated that sequences between nucleotides 41 and 57 define the early boundary of Py DNA replication in vitro. This is consistent with previously published studies on the early-region sequence requirements for Py replication in vivo. Deleting portions of the T-antigen high-affinity binding sites A and B (between nucleotides 57 and 146) on the early-gene side of the core on led to increased levels of replication in vitro and to normal levels of replication in vivo. Point mutations within the core ori region that abolish Py DNA replication in vivo also reduced replication in vitro. A mutant with a reversed orientation of the Py core on region replicated in vitro, but to a lesser extent than wild-type Py DNA. Plasmids with deletions on the late-gene side of the core on, within the enhancer region, that either greatly reduced or virtually abolished Py DNA replication in vivo replicated to levels similar to those of wild-type Py DNA plasmids in vitro. Thus, as has been observed with simian virus 40, DNA sequences needed for Py replication in vivo are different from and more stringent than those required in vitro.Replication of polyomavirus (Py) DNA proceeds bidirectionally from a fixed point within the noncoding region of the viral genome (for a review, see reference 16 and references therein). This replication origin (ori) region (Fig. 1) contains multiple T-antigen (T Ag)-binding sites within a G+C-rich 32-base-pair (bp) sequence of dyad symmetry adjacent to a region in which 13 of 14 residues form A * T pairs. It thus bears structural features similar to the replication ori of simian virus 40 (SV40). However, the relationship of the Py ori to other regulatory signals in the noncoding segment is somewhat different from that of SV40. The number and arrangement of large T Ag high-affinity binding sites on the early side of both viral ori regions differ. Also, the relative affinities of Py and SV40 T Ags for binding sites within their respective ori regions are apparently dissimilar (12,14,28,47). Moreover, while both viruses encode enhancer elements, the Py enhancer is almost directly adjacent to the late boundary of the ori region and consists of a series of discrete elements that bear homologies to other enhancer elements including those of SV40, adenovirus Ela, and mouse immunoglobulin genes (2,22,23,26,31,38,46,51,53). By contrast, the SV40 enhancer, a 72-bp repeated sequence (see reference 22 and references therein), is separated from the core ori by a series of G+C-rich sequences (the 21-bp repeats) that form a distinct transcriptional control element to which the cellular transcription factor, Spl, binds (...

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Section: Discussionmentioning

confidence: 99%

DNA sequence requirements for replication of polyomavirus DNA in vivo and in vitro.

Prives¹,

Murakami²,

Kern³

et al. 1987

Mol. Cell. Biol.

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“…The essential origin sequences are shown (striped bars). DNAinding sites for putative enhancer-specific proteins (open boxes) include PEAl, 2, and 3 (Martin et al 1988); EFC (Fujimura 1986;Ostapuck et al 1986); PEBl (Bohnlein and Gruss 1986;Piette and Yaniv 1986); and F441 (Kovesdi et al 1987). The enhancer region of three PyV host-range mutants selected for growth in undifferentiated mouse embryonal carcinoma F9 cells (Fujimura et al 1981) contains a point mutation at nucleotide 5233 (solid bar, F441), a 31-bp tandem duplication of the mutated region (crosshatched box.…”

Section: Gene Expression In Individual Mouse Oocytes and Embryos Is Pmentioning

confidence: 99%

The need for enhancers in gene expression first appears during mouse development with formation of the zygotic nucleus.

Martínez‐Salas

Linney²,

Hassell³

et al. 1989

Genes Dev.

111

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Microinjection of the firefly luciferase gene coupled to a thymidine kinase (tk) promoter provided a quantitative assay to evaluate the requirements for gene expression in individual mouse oocytes and embryos. Polyoma virus (PyV) enhancers had no effect on the level of gene expression or competition for transcription factors as long as the DNA remained either in the oocyte germinal vesicle or the pronuclei of one-cell embryos. Expression of injected genes could be observed in pronuclei because the signal that normally triggers zygotic gene expression in two-cell embryos still occurred in one-cell embryos arrested in S phase. However, when the tk promoter was injected into zygotic nuclei of two-cell embryos, enhancers increased the number of embryos that expressed luciferase as well as the level of luciferase activity per embryo. PyV enhancer mutation FlOl, selected for growth in mouse embryonal carcinoma F9 cells, stimulated expression in developing two-cell embryos about seven times better than the wild-type PyV enhancer and competed effectively for factors required for transcription. These results were consistent with the fact that enhancers are required to activate the PyV origin of DNA replication in developing two-cell embryos but not in one-cell embryos. The maximum levels of gene expression in oocytes, one-cell embryos, and developing two-cell embryos (1 : 67 : 21) were inversely related to the extent of chromatin assembly, but the need for enhancers was independent of chromatin assembly. Therefore, it appears that the need for enhancers to activate promoters or origins of replication results from some negative regulatory factor that first appears as a component of zygotic nuclear structure.

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“…The activity of enhancer sequences can be modulated by factors in trans as demonstrated by the ability of viral early proteins such as the adenovirus ElA proteins to repress (5,25,49) or stimulate (6, 21, 29) enhancer activity. In addition to viral trans-acting factors, a number of investigators have identified binding sites for nuclear proteins within enhancer sequences (2,3,15,30,37,40,41,47), and there is evidence that the binding of trans-acting proteins regulates enhancer activity (1,4,17,34,35,45,48,53).For both viral and cellular enhancer sequences, host cell specificity has been observed (21, 38), and recent studies have described host cell-specific binding of nuclear proteins to enhancer sequences (2,11,34,35,51). Host cell specificity of enhancer activity could be controlled by the presence or absence of either positively or negatively acting factors.…”

mentioning

confidence: 99%

Negative regulation of the human polyomavirus BK enhancer involves cell-specific interaction with a nuclear repressor.

Grinnell¹,

Berg²,

Walls³

1988

Mol. Cell. Biol.

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We have examined the cell type-specific regulation of the human BK virus (BKV) enhancer. This enhancer functions efficiently in cis to activate expression from the adenovirus major late promoter in the human kidney cell line, 293, and in a monkey kidney cell line, MK2, but not in the HeLa cell line. In gel retardation migration assays, specific BKV enhancer-protein complexes could be observed by using nuclear extracts prepared from each cell line. Moreover, a unique DNA-protein complex was observed by using the HeLa cell nuclear extracts. By DNase footprint analysis, four binding regions for HeLa cell nuclear proteins were defined within the BKV enhancer repeat region. Two of the protected regions encompassed nuclear factor 1 or CCAAT transcription factor binding sites. These nuclear factor 1 sites also were protected by nuclear proteins from the 293 and MK2 cell lines. The other two protected sites encompassed a region of symmetry which included a sequence similar to the simian virus 40 TC enhancer motif and to a conserved sequence present upstream or within the introns of several cellular genes. These two sites were not protected by either the 293 or MK2 nuclear proteins. Competition studies in transfected cells indicated that the reduced activity of the BKV enhancer in the HeLa cell line was due to negative regulation. Further, we have demonstrated that binding of a nuclear factor(s) to the HeLa cell-specific site is involved in the repression of enhancer activity.The control of transcription in eucaryotic cells is a complex process involving the interaction of cellular protein factors with specific gene sequences. A number of trans-and cis-acting elements involved in the regulation of transcription initiation have been described. For example, the cisacting enhancer sequence, first described as a repeat sequence in the regulatory region of simian virus 40 (SV40), can stimulate transcription from homologous and heterologous promoters, independent of position and orientation (for reviews, see references 18 and 32). The activity of enhancer sequences can be modulated by factors in trans as demonstrated by the ability of viral early proteins such as the adenovirus ElA proteins to repress (5,25,49) or stimulate (6, 21, 29) enhancer activity. In addition to viral trans-acting factors, a number of investigators have identified binding sites for nuclear proteins within enhancer sequences (2,3,15,30,37,40,41,47), and there is evidence that the binding of trans-acting proteins regulates enhancer activity (1,4,17,34,35,45,48,53).For both viral and cellular enhancer sequences, host cell specificity has been observed (21, 38), and recent studies have described host cell-specific binding of nuclear proteins to enhancer sequences (2,11,34,35,51). Host cell specificity of enhancer activity could be controlled by the presence or absence of either positively or negatively acting factors. For example, Atchison and Perry (1) suggest the kappa gene is regulated in development by the presence or absence of a positively acting fact...

show abstract

Nuclear activity from F9 embryonal carcinoma cells binding specifically to the enhancers of wild-type polyoma virus and PyEC mutant DNAs

Cited by 49 publications

References 63 publications

DNA sequence requirements for replication of polyomavirus DNA in vivo and in vitro.

DNA sequence requirements for replication of polyomavirus DNA in vivo and in vitro.

The need for enhancers in gene expression first appears during mouse development with formation of the zygotic nucleus.

Negative regulation of the human polyomavirus BK enhancer involves cell-specific interaction with a nuclear repressor.

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