The nucleotide sequence, localization and transcriptional properties of a tRNACUGLeu gene from Drosophila melanogaster

Glew, L; Lo, Reggie Y.C.; Reece, Tove; Nichols, Mark; Söll, Dieter; Bell, John B.

doi:10.1016/0378-1119(86)90195-2

Cited by 9 publications

(8 citation statements)

References 31 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The nonconserved N terminus accounts for nearly half of the molecule in Drosophila topo VOL. 18,1998 FUNCTION OF EUKARYOTIC topo I N TERMINUS 4363 I. As indicated by earlier results with yeast and human topo I (5, 10, 50), topo I from the fruit fly does not require its N terminus for its catalytic activity.…”

Section: Discussionmentioning

confidence: 79%

See 1 more Smart Citation

Targeting to Transcriptionally Active Loci by the Hydrophilic N-Terminal Domain of Drosophila DNA Topoisomerase I

Shaiu

Hsieh

1998

Molecular and Cellular Biology

View full text Add to dashboard Cite

DNA topoisomerase I (topo I) from Drosophila melanogaster contains a nonconserved, hydrophilic N-terminal domain of about 430 residues upstream of the conserved core domains. Deletion of this N terminus did not affect the catalytic activity of topo I, while further removal of sequences into the conserved regions inactivated its enzymatic activity. We have investigated the cellular function of the Drosophila topo I N-terminal domain with top1-lacZ transgenes. There was at least one putative nuclear localization signal within the first 315 residues of the N-terminal domain that allows efficient import of the large chimeric proteins into Drosophila nuclei. The top1-lacZ fusion proteins colocalized with RNA polymerase II (pol II) at developmental puffs on the polytene chromosomes. Either topo I or the top1-lacZ fusion protein was colocalized with RNA pol II in some but not all of the nonpuff, interband loci. However, the fusion proteins as well as RNA pol II were recruited to heat shock puffs during heat treatment, and they returned to the developmental puffs after recovery from heat shock. By immunoprecipitation, we showed that two of the largest subunits of RNA pol II coprecipitated with the N-terminal 315-residue fusion protein by using antibodies against ␤-galactosidase. These data suggest that the topo I fusion protein can be localized to the transcriptional complex on chromatin and that the N-terminal 315 residues were sufficient to respond to cellular processes, especially during the reprogramming of gene expression.Type I DNA topoisomerase (topo I) catalyzes a cycle of transesterification reactions, during which it generates transient single-strand DNA breaks; these reversible reactions result in the topological transformation of either single-strand or double-strand DNA molecules (8,20,55). Biochemical and genetic studies have demonstrated that topo I plays important roles in DNA replication, transcription, and recombination and in chromosome condensation and the maintenance of genome stability. The top1 gene is not essential for viability in yeast, and genetic analysis suggests that some of the biological functions of topo I can be performed by topo II (59). However, recent genetic screens of Saccharomyces cerevisiae have identified four complementation groups of mutants with mutations that, in combination with a top1 mutation, result in a lethal phenotype. Some of these synthetic lethal mutants have mutations in genes other than top2 (44). Therefore, it is possible that not all the biological functions of topo I can be substituted by topo II. Furthermore, because top1 is an essential gene in Drosophila melanogaster (30) and in mice (37), the functions of topo I may not be efficiently substituted by topo II in multicellular organisms.One of the functions of topo I is to provide a swivel to facilitate the unwinding of the DNA duplex during the process of transcription or replication (56). Diametric DNA supercoiling can transiently accumulate in the front and in the wake of a transcriptional fork as proposed...

show abstract

Section: Discussionmentioning

confidence: 79%

“…For example, cytogenetic position 66B (Fig. 5c) is known to contain a cluster of tRNA genes (14,18), and this region is enriched in the top1-lacZ fusion protein but not in RNA pol IIo. It remains to be demonstrated if this locus is truly enriched in RNA pol III.…”

Section: Vol 18 1998 Function Of Eukaryotic Topo I N Terminus 4361mentioning

confidence: 99%

Targeting to Transcriptionally Active Loci by the Hydrophilic N-Terminal Domain of Drosophila DNA Topoisomerase I

Shaiu

Hsieh

1998

Molecular and Cellular Biology

View full text Add to dashboard Cite

show abstract

“…The protocol of Pardue and Gall (1975) as modified by Glew et al (1986) was used for in situ hybridizations. Labeled probes were nick translated as in Maniatis et al (1982).…”

Section: In Situ Hybridizationsmentioning

confidence: 99%

Molecular organization of the vestigial region in Drosophila melanogaster.

Williams

Bell

1988

The EMBO Journal

View full text Add to dashboard Cite

The vestigial (vg) locus of Drosophila melanogaster is involved in wing margin development. In the absence of a vg+ gene, extensive cell death occurs in third instar imaginal discs which results in a complete loss of adult wing margin structures. P‐element tagging was used to obtain a molecular clone of the vg locus, which led to the molecular characterization of approximately 46 kb of DNA from the region. Deficiency analysis and molecular mapping identified sequences, spanning approximately 20 kb of DNA within the larger region, which are necessary for vg function. The molecular map was oriented with respect to a pre‐existing genetic fine structure map of the locus. The centromere distal limits of the locus were defined by deficiency analyses while the proximal end has not yet been conclusively established. However, three transcripts, that are apparently unrelated to vg, provide circumstantial evidence for the proximal limits of the vg locus. The nature of the molecular lesions for several extant recessive or lethal vg alleles was determined, and these were placed on the vg molecular map. The characterization of the lesions associated with two dominant vg alleles and one complex vg allele imply interesting regulatory mechanisms for this locus. As well, a revertant of a 412 insertion mutant allele was shown to have resulted from a further insertion of a roo element into the 412 element.

show abstract

“…We found two extremely conserved motifs located in introns 5 and 7 of Ce gpa-1 (introns 4 and 6 of Cb gpa-1). The latter is predicted to be a tRNA-Leu(CAG) when analysed using the program tRNAscan-SE (Lowe and Eddy 1997; available online at http://www.genetics.wustl.edu/eddy/ tRNAscan-SE) and shows strong similarities to the previously characterized Drosophila melanogaster tRNA-Leu(CUG) (Glew et al 1986). However, the motif located in Ce gpa-1 intron 5, here named D1, showed no evidence of being a tRNA.…”

Section: Conservation Of a Non-coding Motifmentioning

confidence: 97%

Functional constraint and divergence in the G protein family in Caenorhabditis elegans and Caenorhabditis briggsae

Jovelin

Phillips

2005

Mol Genet Genomics

View full text Add to dashboard Cite

Part of the challenge of the post-genomic world is to identify functional elements within the wide array of information generated by genome sequencing. Although cross-species comparisons and investigation of rates of sequence divergence are an efficient approach, the relationship between sequence divergence and functional conservation is not clear. Here, we use a comparative approach to examine questions of evolutionary rates and conserved function within the guanine nucleotide-binding protein (G protein) gene family in nematodes of the genus Caenorhabditis. In particular, we show that, in cases where the Caenorhabditis elegans ortholog shows a loss-of-function phenotype, G protein genes of C. elegans and Caenorhabditis briggsae diverge on average three times more slowly than G protein genes that do not exhibit any phenotype when mutated in C. elegans, suggesting that genes with loss of function phenotypes are subject to stronger selective constraints in relation to their function in both species. Our results also indicate that selection is as strong on G proteins involved in environmental perception as it is on those controlling other important processes. Finally, using phylogenetic footprinting, we identify a conserved non-coding motif present in multiple copies in the genomes of four species of Caenorhabditis. The presence of this motif in the same intron in the gpa-1 genes of C. elegans, C. briggsae and Caenorhabditis remanei suggests that it plays a role in the regulation of gpa-1, as well as other loci.

show abstract

The nucleotide sequence, localization and transcriptional properties of a tRNACUGLeu gene from Drosophila melanogaster

Cited by 9 publications

References 31 publications

Targeting to Transcriptionally Active Loci by the Hydrophilic N-Terminal Domain of Drosophila DNA Topoisomerase I

Targeting to Transcriptionally Active Loci by the Hydrophilic N-Terminal Domain of Drosophila DNA Topoisomerase I

Molecular organization of the vestigial region in Drosophila melanogaster.

Functional constraint and divergence in the G protein family in Caenorhabditis elegans and Caenorhabditis briggsae

Contact Info

Product

Resources

About