Relationship between the two components of the split promoter of eukaryotic tRNA genes.

Ciliberto, Gennaro; Traboni, Cinzia; Cortese, Riccardo

doi:10.1073/pnas.79.6.1921

Cited by 74 publications

(37 citation statements)

References 23 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Binding to the two sites was independent of the relative orientation of the two sites on the helix and was eliminated by a single point mutation in the 3' promoter. The chromosomal tRNAsU'P53 and tRNAUCG genes showed a pattern of protection and enhanced cleavages similar to that observed in vitro, indicating that the stable complexes formed in vitro accurately reflect at least some aspects of the nucleoprotein structure of the genes in chromatin.The transcription of eucaryotic tRNA genes is controlled by two highly conserved intragenic sequence elements located near the 5' and 3' ends of the genes, termed the A and B blocks, and by more variable sequences near the site of transcription initiation (9,16,18,38,40; reviewed in reference 39). The internal elements are also essential to tRNA processing and function, even in procaryotes, and may therefore have evolved into ubiquitous eucaryotic promoters as tRNA genes became independent transcription units.…”

mentioning

confidence: 99%

Comparison of tRNA gene transcription complexes formed in vitro and in nuclei.

1987

View full text Add to dashboard Cite

The nucleoprotein structure of single-copy tRNA genes in yeast nuclei was examined by DNase I footprinting and compared with that of complexes formed in vitro between the same genes and transcription factor C.Transcription factor C bound to both the 5' and 3' intragenic promoters of the tRNASUP53 gene in vitro, protecting approximately 30 base pairs at the 3' promoter (B block) and 40 base pairs at the 5' promoter (A block) and causing enhanced DNase I cleavages between the protected regions. Binding to the two sites was independent of the relative orientation of the two sites on the helix and was eliminated by a single point mutation in the 3' promoter. The chromosomal tRNAsU'P53 and tRNAUCG genes showed a pattern of protection and enhanced cleavages similar to that observed in vitro, indicating that the stable complexes formed in vitro accurately reflect at least some aspects of the nucleoprotein structure of the genes in chromatin.The transcription of eucaryotic tRNA genes is controlled by two highly conserved intragenic sequence elements located near the 5' and 3' ends of the genes, termed the A and B blocks, and by more variable sequences near the site of transcription initiation (9,16,18,38,40; reviewed in reference 39). The internal elements are also essential to tRNA processing and function, even in procaryotes, and may therefore have evolved into ubiquitous eucaryotic promoters as tRNA genes became independent transcription units. The upstream sequences have been shown to influence transcription in a species-specific manner (10, 12, 40) and have been postulated to impose differential regulation on classes of tRNA genes within an organism (14,23,29,47). The precise mechanism by which these promoter elements direct RNA polymerase III initiation is not clear, but an early step in gene activation appears to be the association of one or more transcription factors with the A and B blocks.Fractionation of cellular extracts has identified at least two components, transcription factor B (TFIIIB) and TFIIIC, that are required in addition to RNA polymerase III for tRNA transcription in vitro (17,28,37). TFIIIC contains an activity that binds to both the A and B regions in vitro (7,8,44) and remains bound through multiple rounds of gene transcription (3,17,34). Experiments with altered tRNA gene templates have shown that binding is primarily directed by the B block, although A block mutations lower the overall binding efficiency and drastically reduce promoter strength (2,7,31,44). The function of TFIIIB is unclear, although it has been shown to be necessary for the formation of stable preinitiation complexes in some cases (3).The spacing between the A and B block promoter regions varies from 30 to 80 base pairs in naturally occurring tRNA genes (9, 39, 41). The binding of a single TFIIIC complex to two sites separated by such a variable length of DNA would require considerable flexibility in the structure of the factor. It has been proposed instead that the DNA is contorted to allow the promoter elements to attain...

show abstract

mentioning

confidence: 99%

Comparison of tRNA gene transcription complexes formed in vitro and in nuclei.

1987

View full text Add to dashboard Cite

show abstract

“…At least two separated 10 base pair (bp) long DNA segments have been characterized: Box A, coding for nucleotides 9-18, and Box B coding for nucleotides 53-61 of the corresponding tRNA molecule Galli et al, 1981;Ciliberto et al, 1982aCiliberto et al, , 1982b. In contrast, in prokaryotic tRNA genes, the sequence essential for promotion of transcription (the promoter) is localized upstream to the coding sequence in the 5'-flanking region (Rosenberg and Court, 1979;Berman and Landy, 1979).…”

Section: Introductionmentioning

confidence: 99%

“…The sequence between these two regions contains important, but not essential, information for transcription (Ciampi et al, 1982). The two essential elements (Box A and Box B) are both required but constitute independent transcriptional signals: a transcriptionally active hybrid gene could be constructed containing Box A and Box B derived from different genes (Galli et al, 1981;Ciliberto et al, 1982b).…”

Section: Introductionmentioning

confidence: 99%

“…Injection of these plasmids into oocytes, shows that the E. coli tRNATYr gene is not transcribed even in the presence of a 'compatible' flanking region. E. coli tDNATyr-C. elegans tDNAPrm 'hybrid' genes It has been shown that the eukaryotic tRNA gene promoter is composed of two essential and separate elements corresponding to the coding sequences of part of the tRNA D-loop and stem (5' component of Box A) and of tRNA T stem and loop (3' component of Box B) Galli et al, 1981;Ciliberto et al, 1982aCiliberto et al, , 1982b. The sequence between these two regions contains important, but not essential, information for transcription (Ciampi et al, 1982).…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

A prokaryotic tRNATyr gene, inactive in Xenopus laevis oocytes, is activated by recombination with an eukaryotic tRNAPro gene.

Dente¹,

Fasano²,

Costanzo³

et al. 1982

The EMBO Journal

View full text Add to dashboard Cite

Eukaryotic tDNA promoters are composed of two essential regions contained within the coding sequence (Box A and Box B). Due to the highly conserved structure of prokaryotic and eukaryotic tRNA, most prokaryodic tRNA genes are expected to be active templates in eukaryotic transcriptional systems. In this paper we show that Escherichia coli tDNATYr is not transcribed in the nucleus of Xenopus laevis oocytes. By in vitro construction of hybnd molecules between inactive prokaryotic tDNATYr from E. coli, and active eukaryotic tDNAPrm from Caenorhabditis elegans, we show that tDNATYr can be made into an active gene if its first third, including the Box A region, is replaced by that of the eukaryotic tDNA. These results suggest that an improper Box A sequence is responsible for the inactivity of the E. coli tRNATYr gene, and argue against the role of secondary and tertiary DNA confonnations in RNA polymerse III transcripion.

show abstract

“…The formation of eucaryotic tRNA precursors by RNA polymerase III and specific transcription factors (3,15,31,36,41) is regulated by two internal control regions (4,6,14,16,20,38,40). Transcription of tRNA genes is also affected by elements in the 5'-flanking sequence.…”

mentioning

confidence: 99%

Transcription factor binding is limited by the 5'-flanking regions of a Drosophila tRNAHis gene and a tRNAHis pseudogene.

Cooley¹,

Schaack²,

Burke³

et al. 1984

Mol. Cell. Biol.

View full text Add to dashboard Cite

We determined the sequence of a Drosophila tRNA gene cluster containing a tRNAHis gene and a tRNAHis pseudogene in close proximity on the same DNA strand. The pseudogene contains eight consecutive base pairs different from the region of the bona fide gene which codes for the 3' portion of the anticodon stem of tRNAHis. The tRNAHis gene is transcribed efficiently in Drosophila Kc cell extract, whereas the pseudogene is not. The pseudogene is also a much poorer competitor than the real gene in a stable transcription complex formation assay, even though the sequence alteration in the pseudogene does not affect the sequence or spacing of the putative internal transcription control regions. Recombinant clones were constructed in which the 5'-flanking regions are exchanged. The transcription efficiencies and competitive abilities of the recombinant clones resemble those of the genes from which the 5' flank was derived; for example, the tRNAHis pseudogene with the 5'-flanking sequence of the tRNAHis gene is now efficiently transcribed. Deletion analysis of the pseudogene 5' flank failed to uncover an inhibitory element. Deletion analysis of the real gene showed very high dependence on the presence of the wild-type 5'-flanking sequence for factor binding to the internal control regions and stable complex formation. The 5'-flanking sequence of a Drosophila tRNAArg gene active in the Drosophila Kc cell extract does not restore transcriptional activity or stable complex formation. The tRNAHis gene and pseudogene behave atypically in HeLa cell extract. Both genes compete for HeLa transcription factors, but neither of them is efficiently transcribed. Removal of the 5'-flanking sequences of each gene and replacement with various sequences, including the tRNAArg gene 5' flank, does not allow increased transcription in HeLa cell extract.

show abstract

Relationship between the two components of the split promoter of eukaryotic tRNA genes.

Cited by 74 publications

References 23 publications

Comparison of tRNA gene transcription complexes formed in vitro and in nuclei.

Comparison of tRNA gene transcription complexes formed in vitro and in nuclei.

A prokaryotic tRNATyr gene, inactive in Xenopus laevis oocytes, is activated by recombination with an eukaryotic tRNAPro gene.

Transcription factor binding is limited by the 5'-flanking regions of a Drosophila tRNAHis gene and a tRNAHis pseudogene.

Contact Info

Product

Resources

About