Regions upstream from the core promoter of the rat ribosomal gene are required for the formation of a stable transcription initiation complex by RNA polymerase I in vitro

Cassidy, B. G.; Haglund, R. E.; Rothblum, Lawrence I.

doi:10.1016/0167-4781(87)90035-2

Cited by 27 publications

(25 citation statements)

References 24 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…That region of the promoter ( 31 to + 6) sufficient for transcription in vitro, and essential for transcription in vivo is referred to as the core promoter element (CPE). However, when 5'-deletion mutant and wild-type promoters compete against one another under conditions where the levels of the transcription factors are limiting, a requirement for distal sequences becomes apparent (5,12). In vivo experiments demonstrate that constructs with only the CPE are essentially inactive (7).…”

Section: Introductionmentioning

confidence: 99%

“…Two distal elements, the upstream promoter element (UPE) and a promoterproximal terminator (referred to as T. in mammals, and as T3 in Xenopus) have been identified (8,9,10). The UPE has been shown to be required for transcription in vivo (7), for elevated levels of transcription in vitro, and it appears to be required for the formation of the stable preinitiation complex (11,12,13). Furthermore, there is a required stereospecific alignment of the UPE and the CPE (35).…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Analysis of the rat ribosomal DNA promoter: characterization of linker-scanning mutants and of the binding of UBF

et al. 1992

Self Cite

View full text Add to dashboard Cite

To investigate the mechanism of transcription of the rat ribosomal DNA (rDNA) promoter, a series of 23 linker-scanning mutants were constructed and assayed in transfected CHO cells and with cell-free extracts. With minor variation, the results of the in vitro and in vivo assays paralleled one another. For example, these assays demonstrated that the mutagenesis of bases from -133 to -124, and those from -106 to -101 of the rDNA promoter significantly inhibited transcription both in vivo and in vitro. Both of these sites lie within the upstream promoter element (UPE) of the rDNA promoter. Several constructs, in particular one that mutated the bases between -49 and -45, were better promoters in vivo than the wild-type promoter. DNAse footprinting experiments with purified UBF, an RNA polymerase I transcription factor, demonstrated the importance of the bases between -106 and -101 for the binding of that factor, providing a positive correlation between the transcription experiments and the binding of UBF to the rDNA promoter.

show abstract

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Analysis of the rat ribosomal DNA promoter: characterization of linker-scanning mutants and of the binding of UBF

et al. 1992

Self Cite

View full text Add to dashboard Cite

show abstract

“…The core promoter element, located between nucleotides -39 and +6 (+1 being the initiation site of the precursor rRNA), is required for the correct initiation of transcription (14,25,29,33,60). The upstream promoter (or control) element, located between nucleotides -150 and -110, has been shown to be able to effectively stabilize the preinitiation complex (3,20,38,52,55). Transcription terminators have been identified both downstream and upstream of the initiation site (15,16,36).…”

mentioning

confidence: 99%

Purification and characterization of a high-mobility-group-like DNA-binding protein that stimulates rRNA synthesis in vitro.

Yang-Yen¹,

Rothblum²

1988

Mol. Cell. Biol.

View full text Add to dashboard Cite

A 16,000-dalton, high-mobility-group-like (HMG-like) DNA-binding protein, referred to as p16, has been purified to homogeneity from Novikoff hepatoma ascites cells. p16 binds specifically to a portion of the 5' flanking region of the rat rRNA gene (-620 to -417), which is part of the upstream activator sequence identified previously (B. G. Cassidy, H.-F. Yang-Yen, and L. I. Rothblum, Mol. Cell. Biol. 6:2766-2773, 1986). p16 also binds to a segment of the external transcribed spacer (+352 to +545). In vitro reconstituted transcription experiments demonstrated that the addition of p16 stimulated rRNA synthesis up to ca. fourfold. The stimulation was dose dependent and saturable. The effect of p16 on ribosomal gene transcription was also dependent on the presence of either the upstream or the downstream DNA-binding site, or both. The amino acid composition of p16 is very similar to that of HMG-I, suggesting that p16 may be a member of the HMG-I family of proteins. In this case, our results suggest that HMG proteins may play an important role in the regulation of the rRNA gene expression.

show abstract

“…Functional analysis of the promoters of the mammalian rRNA genes indicates that despite significant sequence differences, the promoters apparently consist of elements with similar functions. That region of the promoter (--31 to -+6) required for transcription in vitro (5,12,16,26,43) is referred to as the core promoter element (CPE). Under more stringent conditions, a requirement for distal sequences becomes apparent (33), and in vivo, the CPE is almost inactive (40).…”

mentioning

confidence: 99%

Characterization of factors that direct transcription of rat ribosomal DNA.

et al. 1990

View full text Add to dashboard Cite

The protein components that direct and activate accurate transcription by rat RNA polymerase I were studied in extracts of Novikoff hepatoma ascites cells. A minimum of at least two components, besides RNA polymerase I, that are necessary for efficient utilization of templates were identified. The first factor, rat SL-1, is required for species-specific recognition of the rat RNA polymerase I promoter and may be sufficient to direct transcription by pure RNA polymerase I. Rat SL-1 directed the transcription of templates deleted to -31, the 5' boundary of the core promoter element (+ 1 being the transcription initiation site). The second factor, rUBF, increased the efficiency of template utilization. Transcription of deletion mutants indicated that the 5' boundary of the domain required for rUBF lay between -137 and -127. Experiments using block substitution mutants confirmed and extended these observations. Transcription experiments using those mutants demonstrated that two regions within the upstream promoter element were required for optimal levels of transcription in vitro. The first region was centered on nucleotides -129 and -124. The 5' boundary of the second domain mapped to between nucleotides -106 and -101. DNase footprint experiments using highly purified rUBF indicated that rUBF bound between -130 and -50. However, mutation of nucleotides -129 and -124 did not affect the rUBF footprint. These results indicate that basal levels of transcription by RNA polymerase I may require only SL-1 and the core promoter element. However, higher transcription levels are mediated by additional interactions of rUBF, and possibly SL-1, bound to distal promoter elements.Eucaryotic rRNA genes (rDNAs) code for three of the four rRNA molecules (18S, 5.8S, and 28S rRNAs). These three RNAs are products of degradative processing of a larger precursor (40S to 47S pre-rRNA). The genes that serve as the template for this transcription are present in multiple copies (approximately 200 per haploid genome) and are organized as clusters of tandem repeats. In interphase cells, the genes are localized to the nucleolus, where they are transcribed by RNA polymerase I. Each repeat consists of a transcribed portion and a nontranscribed spacer (reviewed in references 27 and 28). In at least two species, Xenopus laevis and Drosophila melanogaster, the nontranscribed spacer is transcribed (9,23,41), and at least part of the nontranscribed spacer of the rat repeat is transcribed from a spacer promoter (6), suggesting that the name of this region needs to be changed.The transcription initiation sites of several mammalian rRNA genes have been identified and sequenced. Functional analysis of the promoters of the mammalian rRNA genes indicates that despite significant sequence differences, the promoters apparently consist of elements with similar functions. That region of the promoter (--31 to -+6) required for transcription in vitro (5,12,16,26, 43) is referred to as the core promoter element (CPE). Under more stringent conditions, a requirement...

show abstract

Regions upstream from the core promoter of the rat ribosomal gene are required for the formation of a stable transcription initiation complex by RNA polymerase I in vitro

Cited by 27 publications

References 24 publications

Analysis of the rat ribosomal DNA promoter: characterization of linker-scanning mutants and of the binding of UBF

Analysis of the rat ribosomal DNA promoter: characterization of linker-scanning mutants and of the binding of UBF

Purification and characterization of a high-mobility-group-like DNA-binding protein that stimulates rRNA synthesis in vitro.

Characterization of factors that direct transcription of rat ribosomal DNA.

Contact Info

Product

Resources

About