The Specificity of S-Adenosylmethionine Derivatives in Methyl Transfer Reactions

Zappia, Vincenzo; Zydek-Cwick, Cynthia R.; Schlenk, F.

doi:10.1016/s0021-9258(18)94346-2

Cited by 275 publications

(26 citation statements)

References 38 publications

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“…Accumulation of SAH and SAM in the mutant are presumably due to inhibition 171 of SAH hydrolase upon increased intracellular adenine (Fig. 2j) (Knudsen and Yall, 1972) and to 172 inhibition of methyl-transferases by SAH (Zappia et al, 1969), respectively ( Fig. 1, green dashed lines).…”

Section: Results 150mentioning

confidence: 99%

Genetic investigation of purine nucleotide imbalance in Saccharomyces cerevisiae

et al. 2020

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Because metabolism is a complex balanced process involving multiple enzymes, understanding how 39 organisms compensate for transient or permanent metabolic imbalance is a challenging task that can be 40 more easily achieved in simpler unicellular organisms. The metabolic balance results from the 41 combination of individual enzymatic properties, regulation of enzyme abundance, but also from the 42 architecture of the metabolic network offering multiple interconversion alternatives. Although metabolic 43 networks are generally highly resilient to perturbations, metabolic imbalance resulting from enzymatic 44 defect and specific environmental conditions can be designed experimentally and studied. Starting with 45 a double amd1 aah1 mutant that severely and conditionally affects yeast growth, we carefully 46 characterized the metabolic shuffle associated with this defect. We established that the GTP decrease 47resulting in an adenylic/guanylic nucleotide imbalance was responsible for the growth defect. 48Identification of several gene dosage suppressors revealed that TAT1, encoding an amino acid 49 transporter, is a robust suppressor of the amd1 aah1 growth defect. We show that TAT1 suppression 50 occurs through replenishment of the GTP pool in a process requiring the histidine biosynthesis pathway. 51Importantly, we establish that a tat1 mutant exhibits synthetic-sickness when combined with an amd1 52 mutant and that both components of this synthetic phenotype can be suppressed by specific gene dosage 53 suppressors. Together our data point to a strong phenotypic connection between amino acid uptake and 54 GTP synthesis, a connection that could open perspectives for future treatment of related human defects, 55 previously reported as etiologically highly conserved.

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Section: Results 150mentioning

confidence: 99%

Genetic investigation of purine nucleotide imbalance in Saccharomyces cerevisiae

et al. 2020

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“…Deamination of S‐adenosyl homocysteine (SAH) converts SAH into S‐inosine homocysteine (SIH). SAH is a potent inhibitor of DNA methyltransferases (DMTs; James et al, 2002 ) but SIH does not inhibit DMTs (Zappia et al, 1969 ). There was also high similarity (73%) to the mammalian and bacterial guanine deaminase (GDA) with critical identity in substrate binding and catalytic sites.…”

Section: Resultsmentioning

confidence: 99%

“…The closest similarity to functionally characterized genes was 86.74% to the Ricinus atrazine chlorohydrolase and 70% to the Clostridium Sadenosyl homocysteine deaminase (SAHD). The predicted protein sequence BLAST for LOC_Os12g28270 also revealed high similarity (Zappia et al, 1969). There was also high similarity (73%) to the mammalian and bacterial guanine deaminase (GDA) with critical identity in substrate binding and catalytic sites.…”

Section: The Rice Amidohydrolase On Chromosome 12 Is a Guanine Deaminasementioning

confidence: 89%

A drought‐responsive rice amidohydrolase is the elusive plant guanine deaminase with the potential to modulate the epigenome

Gotarkar

Longkumer

Yamamoto

et al. 2021

Physiologia Plantarum

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Drought stress in plants causes differential expression of numerous genes. One of these differentially expressed genes in rice is a specific amidohydrolase. We characterized this amidohydrolase gene on the rice chromosome 12 as the first plant guanine deaminase (OsGDA1). The biochemical activity of GDA is known from tea and coffee plants where its catalytic product, xanthine, is the precursor for theine and caffeine. However, no plant gene that is coding for GDA is known so far. Recombinant OsGDA1 converted guanine to xanthine in vitro. Measurement of guanine and xanthine contents in the OsGDA1 knockout (KO) line and in the wild type Tainung 67 rice plants also suggested GDA activity in vivo. The content of cellular xanthine is important because of its catabolic products allantoin, ureides, and urea which play roles in water and nitrogen stress tolerance among others. The identification of OsGDA1 fills a critical gap in the S-adenosyl-methionine (SAM) to xanthine pathway. SAM is converted to S-adenosyl-homocysteine (SAH) and finally to xanthine. SAH is a potent inhibitor of DNA methyltransferases, the reduction of which leads to increased DNA methylation and gene silencing in Arabidopsis. We report that the OsGDA1 KO line exhibited a decrease in SAM, SAH and adenosine and an increase in rice genome methylation. The OsGDA1 protein phylogeny combined with mutational protein destabilization analysis suggested artificial selection for null mutants, which could affect genome methylation as in the KO line. Limited information on genes that may affect epigenetics indirectly requires deeper insights into such a role and effect of purine catabolism and related genetic networks. Dhananjay Gotarkar and Toshisangba Longkumer have contributed equally to this study.

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“…Alkaline hydrolysis in 0.1 m NaOH at 100 °C also yielded adenine and 3-methyl thiopropylamine as the main products. Milder alkaline hydrolysis, namely in 0.1 m NaOH at 25 °C, was carried out, followed by spectrophotometry at 250 nm (Parks & Schlenk 1957;Zappia, Zydek-Cwick & Schlenk 1969); after 10 min the readings were constant and the absorbance was 55 % of the original value. The resulting spectrum and that after acidification were characteristic of adenine.…”

Section: R Esultsmentioning

confidence: 99%

“…Heating AMe a t 100 °C and pH 4.8 resulted in the liberation of 5'-methylthioadenosine and homoserine (de la Haba, Jamieson, Mudd & Richard 1959). 5'-Methylthioadenosine and 3-amino-l-propanol were liberated by hydrolysis a t 100 °C and pH 4 of decarboxylated AMe synthesized enzymically from AMe (Zappia et al 1969).…”

Section: Decarboxylatedmentioning

confidence: 99%

Identification of decarboxylated S -adenosylmethionine in the tapetum lucidum of the catfish

1975

Proc. R. Soc. Lond. B.

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The chemistry of the tapetum lucidum of the sea catfish ( Arius felis ) was investigated. The reflecting material consists of two components – one, a tapetal pigment consisting of oligomers of 5, 6-dihydroxyindole-2-carboxylic acid, and another consisting of basic u. v. absorbing materials – which were studied. A main constituent of the latter was isolated by ion-exchange chromatography and precipitation as a flavinate. Chemical properties of this compound indicated its structure to be decarboxylated S -adenosylmethionine and this was confirmed by comparison with a synthetic sample. Thiamine was also identified as a minor constituent. A quantitative analysis of reflecting material purified by centrifugation showed that tapetal pigment, decarboxylated S -adenosylmethionine, and thiamine constituted 44, 17, and 2%, respectively, of the dry mass.

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The Specificity of S-Adenosylmethionine Derivatives in Methyl Transfer Reactions

Cited by 275 publications

References 38 publications

Genetic investigation of purine nucleotide imbalance in Saccharomyces cerevisiae

Genetic investigation of purine nucleotide imbalance in Saccharomyces cerevisiae

A drought‐responsive rice amidohydrolase is the elusive plant guanine deaminase with the potential to modulate the epigenome

Identification of decarboxylated S -adenosylmethionine in the tapetum lucidum of the catfish

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