Analysis of the mouse dhfr promoter region: existence of a divergently transcribed gene.

Crouse, Gray F.; Leys, E J; McEwan, R N; Frayne, E G; Kellems, Rodney E.

doi:10.1128/mcb.5.8.1847

Cited by 103 publications

(77 citation statements)

References 24 publications

(33 reference statements)

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“…The mouse dihydrofolate reductase gene has been cloned (6) and the transcription initiation sites (5,17,21) and polyadenylation sites (24; Hook and Kellems, submitted) have been mapped (Fig. 1A).…”

Section: Resultsmentioning

confidence: 99%

“…Two transcription promoter domains have been functionally identified on the basis of gene transfer and expression in cultured mammalian cells (17). Nuclease protection analyses have identified two transcription start regions, each of which display microheterogeneity of initiation sites (5,17,21). Transcription initiation sites at positions -55 and -115 (relative to the ATG codon of dhfr) are governed by the major dhfr promoter.…”

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confidence: 99%

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Independent 5' and 3'-end determination of multiple dihydrofolate reductase transcripts.

Yen¹,

Kellems²

1987

Mol. Cell. Biol.

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Multiple dihydrofolate reductase (dhfr) mRNAs, differing substantially in abundance, are produced as a result of the utilization of multiple transcription initiation sites and multiple polyadenylation sites. We have shown that dhfr mRNAs initiating from an upstream promoter region utilize the same collection of six polyadenylation sites and generate multiple dhfr mRNAs at the same relative abundance as do the mRNAs initiating from the major transcription promoter region. These results indicate that the 5' and 3' ends of dhfr mRNAs are independently determined. We show that the relative abundance of steady-state dhfr mRNAs was the same in nuclear and cytoplasmic RNA fractions. This finding makes it unlikely that differences in mRNA stability account for differences in the relative abundance of the multiple dhfr mRNAs in the cytoplasm. Our analysis of the dhfr promoter region revealed the existence of stable cytoplasmic polyadenylated transcripts complementary to the first 300 nucleotides of the dhfr transcripts initiating from the upstream promoter region. Therefore, the dhfr locus hosts two divergent and partially overlapping genes which share the same promoter region.

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Section: Resultsmentioning

confidence: 99%

mentioning

confidence: 99%

Independent 5' and 3'-end determination of multiple dihydrofolate reductase transcripts.

Yen¹,

Kellems²

1987

Mol. Cell. Biol.

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“…Detailed mutational analysis will be required to determine the exact regulatory requirements of this promoter. Bidirectional transcription has never been reported for an oncogene but has been described in a number of other genes, including the SV40 early and late promoters (26), the dihydrofolate reductase gene (16,45), and human mitochondrial promoters (13). These genes are associated with GC boxes and multiple initiation sites.…”

Section: Discussionmentioning

confidence: 99%

“…Calcium phosphate precipitates were formed as described by Wigler et al (66). Cells were exposed to precipitates for 14 to 16 h, after which the medium was replaced. In transient transfections, cells were harvested 48 h after addition of DNA.…”

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confidence: 99%

c-Ha-ras gene bidirectional promoter expressed in vitro: location and regulation.

Lowndes¹,

Paul²,

Wu³

et al. 1989

Mol. Cell. Biol.

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Increased transcriptional activity of the c-Ha-ras gene product is correlated with induction of several important human tumor types. For this reason, we have investigated the nature of the c-Ha-ras promoter and the factors that regulate its expression. Using Si and primer extension analysis of c-Ha-ras RNA from EJ cells, we have identified 18 initiation sites within an upstream exon (exon -1) whose 3' end (the donor splice site [DI) is located 1,105 base pairs (bp) upstream of the ATG codon. The furthest-upstream initiation site is located -191 bp relative to D, and the furthest downstream is located -16 bp relative to D. Transient expression assays, in which a series of mutants spanning this region were ligated to a promoterless chloramphenicol acetyltransferase vector, functionally confirmed the position and extent of this promoter. Mutational analysis further located a 47-bp element located between -243 and -196 relative to D that up-regulated transcriptional activity of the promoter region by 20-to 40-fold. This region contained both a GC box known to bind SP1 and a CCAAT box. Insertion of a simian virus 40 enhancer 5' to the promoter up-regulated transcription from each initiation site by approximately 10-to 20-fold. We have also localized, both by chloramphenicol acetyltransferase assay and by SI analysis, a strong promoter operating in the direction opposite that of the gene and originating immediately 5' to the 47-bp regulatory region. The reverse promoter was found to have nine initiation sites between -248 and -278 relative to D.The members of the ras gene family were first identified as cellular homologs of the Harvey and Kirsten sarcoma virus oncogenes (21). Genes bearing a high degree of homology to the mammalian ras family have been identified in organisms from virtually every evolutionary group, including Drosophila (51, 59), yeasts (18), and slime mold (56). In mammals, the ras genes appear to be expressed in all cell types and at all developmental stages (48, 49). The high degree of evolutionary conservation and constitutive expression of these genes in different cell types has led to the suggestion that they fulfill some essential cellular functions (9).The human ras gene family (Ha-ras, K-ras, and N-ras) is highly conserved in the human genome and encodes structurally related proteins of approximately 21,000 daltons (60). The p21 proteins are localized at the plasma membrane (67), bind guanine nucleotides (58), and have weak GTPase activity (43). Furthermore, there is some structural homology between ras proteins and the G protein known to regulate hormone-sensitive adenylate cyclase activity (28). Again, this suggests a crucial role for these genes in cellular control. Direct support for this suggestion has come from several experimental systems. It has been shown that the ras proteins can induce cellular proliferation (5,22,50) and can also influence cellular differentiation (3, 31).Members of the ras oncogene family have been implicated in the etiology of a variety of naturally occurring...

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“…This gene organization was first observed in the investigation of mouse DHFR gene [3]. Subsequently, SURF-1/SURF-2 [4], COL4A1/COL4A2 [1], RanBP1/Htf9-c [5], E14/ATM [6], BRCA1/NBR2 [7], DNA-PKcs/MCM4 [8], FEN1/C11orf10 [9], and so on were identified in human, hamster, rat, or mouse through individual experiments.…”

Section: Introductionmentioning

confidence: 99%

Systematic Analysis of Head-to-head Gene Organization: Evolutionary Conservation and Potential Biological Relevance

Li¹,

Huang²,

Guo³

et al. 2005

PLoS Comp Biol

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Analysis of the mouse dhfr promoter region: existence of a divergently transcribed gene.

Cited by 103 publications

References 24 publications

Independent 5' and 3'-end determination of multiple dihydrofolate reductase transcripts.

Independent 5' and 3'-end determination of multiple dihydrofolate reductase transcripts.

c-Ha-ras gene bidirectional promoter expressed in vitro: location and regulation.

Systematic Analysis of Head-to-head Gene Organization: Evolutionary Conservation and Potential Biological Relevance

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