Fine structure analysis of the Chinese hamster AS gene encoding asparagine synthetase

Andrulis, IL; Shotwell, Mark A.; Evans-Blackler, S; Zalkin, Howard; Siminovitch, Louis; Ray, P. N.

doi:10.1016/0378-1119(89)90252-7

Cited by 13 publications

(10 citation statements)

References 29 publications

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“…On sequencing, 1 clone showed a high degree of homology with hamster and human ASNS 5′ regions (Greco et al, 1989;Andrulis et al, 1989). The mouse sequence from +1 to -1052 includes the entire untranslated exon 1 and a further 953 bp upstream (GenBank Accession # Bank It 333658 AF 262321).…”

Section: Isolation and Characterization Of The Promoter Of Mouse Asnsmentioning

confidence: 99%

Hypermethylation of CpG islands in the mouse asparagine synthetase gene: relationship to asparaginase sensitivity in lymphoma cells. Partial methylation in normal cells

et al. 2001

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Asparagine synthetase (ASNS) is a housekeeping gene responsible for the biosynthesis of L-asparagine (ASN). The gene is expressed constitutively in most mammalian cells and regulates its level of activity in response to the concentration of ASN in the plasma or medium, and the extent of tRNA aminoacylation (Andrulis et al, 1979). In contrast to normal cells, the cells of a number of animal malignancies, especially lymphoid, are ASN auxotrophs that fail to express ASNS. In these, deprivation of exogenous ASN by L-asparaginase (Asnase) induces cell death (Broome, 1963;Boyse et al, 1967). This forms the basis for the clinical use of the enzyme as a therapeutic agent for acute lymphocytic leukaemia (Tallal et al, 1970). In the prototypic mouse system, 6C3HED, an Asnasesensitive lymphoma cell line originating in the C3H strain (here designated 6C3HED-Ade), lacked ASNS activity, as did various similar lymphoma and other cell lines (Patterson and Orr, 1967;Broome, 1968; Horowitz et al, 1968). However, ASNS activity was present in Asnase-resistant variants of 6C3HED (6C3HED-Ind), which grew out during culture in the absence of ASN or after treatment with subcurative doses of enzyme in vivo. The mechanism responsible for the lack of ASNS in the Asnase-sensitive lymphoma cells as opposed to the Asnase-resistant variants has not been studied in recent years, but in addition to theoretical interest, it may be of clinical significance in understanding the responsiveness of acute lymphocytic leukemia to enzyme treatment both initially and during relapse.The regulation of ASNS mRNA by amino acid concentration has transcriptional and post-transcriptional components involving both cis-and trans-acting factors (Guerrini et al, 1993). Within the human ASNS promoter, the amino acid response element is important for both basal activity and regulation of ASNS expression under amino acid starvation. Evidence that indirectly suggested that methylation might play a role in regulating ASNS gene expression came from studies made in conjunction with cloning the human gene. It was shown that transfection with plasmids containing human ASNS cDNA into cells of the ASNdependent Jensen rat sarcoma was capable of conferring protrophy (Andrulis et al, 1987). However, several transfectants with numerous copies of the cDNA exhibited only basal levels of enzyme activity. Treatment of these transfectant cell lines with 5-azacytidine, an inhibitor of DNA methylation, greatly increased the expression of ASNS mRNA, protein and enzyme activity. This was consistent with the finding that 5-azacytidine caused a marked increase in the number of ASN protrophs in cultures of Jensen cells (Sugiyama et al, 1983). However, no full and direct examination of the methylation status of ASNS has been made until now. Our present experiments have characterized the CpG island in the promoter of the mouse ASNS gene and correlated its hypermethylation with inactivation of gene expression in ASN-dependent lymphoma cells. To our surprise, we found that partial methylation in...

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Section: Isolation and Characterization Of The Promoter Of Mouse Asnsmentioning

confidence: 99%

Hypermethylation of CpG islands in the mouse asparagine synthetase gene: relationship to asparaginase sensitivity in lymphoma cells. Partial methylation in normal cells

et al. 2001

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“…Of the 28 amino acid differences, 16 are conservative. An alignment with sequences of E. coli glucosamine 6-phosphate synthase and glutamine PRPP amidotransferase from E. coli and yeast identified asparagine synthetase as an F-type amidotransferase with an NH2-terminal GAT domain followed by a synthetase domain (240).…”

Section: Identification Of Functional Gat and Synthetase Domainsmentioning

confidence: 99%

The Amidotransferases

Zalkin¹

1993

Advances in Enzymology - And Related Areas of Molecular Biology

104

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“…The predicted ASNl peptide, which consists of 584 amino acids, has a M, of 65,546 and an isoelectric point of 6.63. This encoded ASNl enzyme also contains a purF-type Gln-binding domain (consisting of a Cys'-His'02-Asp29 triad [Mei and Zalkin, 19891) found at the N terminus of various AS peptides (Andrulis et al, 1987(Andrulis et al, , 1989Gong and Basilico, 1990;Richards and Schuster, 1992;Davis and King, 1993) (Fig. 1).…”

Section: Cln-dependent As Of Arabidopsis Contains a Purl:-type Gln-bimentioning

confidence: 99%

“…King, 1993); Ps-AS1, pea AS1 (Tsai and Coruzzi, 1990); Ps-AS2, pea AS2 (Tsai and Coruzzi, 1990); Eco-AsnB, E. coli AsnB (Scofield et al, 1990); Hum-AS, human AS (Andrulis et al, 1987). AS peptides of Chinese hamster (Andrulis et al, 1989) and Syrian hamster (Gong and Basilico, 1990) share high homology to human AS and have a conserved purf-type Glnbinding triad. For simplicity, only the human AS sequence is shown; other animal AS peptide sequences are highly homologous to human AS.…”

Section: A E S -V P S T P Y E P L a -------I~f~a V I~~d V P F G V L Lmentioning

confidence: 99%

Metabolic Regulation of the Gene Encoding Glutamine-Dependent Asparagine Synthetase in Arabidopsis thaliana

1994

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Here, we characterize a cDNA encoding a glutamine-dependent asparagine synthetase (ASN7) from Arabidopsis thaliana and assess the effects of metabolic regulation on ASNl mRNA levels. Sequence analysis shows that the predicted ASNl peptide contains a purFtype glutamine-binding domain. Southern blot experiments and cDNA clone analysis suggest that ASNl is the only gene encoding glutamine-dependent asparagine synthetase in A. thaliana. The ASNl gene is expressed predominantly in shoot tissues, where light has a negative effect on its mRNA accumulation. This negative effect of light on ASNl mRNA levels was shown to be mediated, at least in part, via the photoreceptor phytochrome. We also investigated whether light-induced changes in nitrogen to carbon ratios might exert a metabolic regulation of the ASNl mRNA accumulation. These experiments demonstrated that the accumulation of ASNl mRNA in dark-grown plants is strongly repressed by the presence of exogenous sucrose. Moreover, this sucrose repression of ASNl expression can be partially rescued by supplementation with exogenous amino acids such as asparagine, glutamine, and glutamate. These findings suggest that the expression of the ASNl gene is under the metabolic control of the nitrogen to carbon ratio in cells. This is consistent with the fact that asparagine, synthesized by the ASNl gene product, is a favored compound for nitrogen storage and nitrogen transport in dark-grown plants. We have put forth a working model suggesting that when nitrogen to carbon ratios are high, the gene product of ASNl functions to re-direct the flow of nitrogen into asparagine, which acts as a shunt for storage and/or long-distance transport of nitrogen.

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Fine structure analysis of the Chinese hamster AS gene encoding asparagine synthetase

Cited by 13 publications

References 29 publications

Hypermethylation of CpG islands in the mouse asparagine synthetase gene: relationship to asparaginase sensitivity in lymphoma cells. Partial methylation in normal cells

Hypermethylation of CpG islands in the mouse asparagine synthetase gene: relationship to asparaginase sensitivity in lymphoma cells. Partial methylation in normal cells

The Amidotransferases

Metabolic Regulation of the Gene Encoding Glutamine-Dependent Asparagine Synthetase in Arabidopsis thaliana

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