Medicines associated with folate–homocysteine–methionine pathway disruption

2018 ◽  
Vol 93 (2) ◽  
pp. 227-251 ◽  
Author(s):  
M. Vidmar ◽  
J. Grželj ◽  
I. Mlinarič-Raščan ◽  
K. Geršak ◽  
M. Sollner Dolenc
Keyword(s):  
Methionine Pathway

scholarly journals Mitochondrial metabolism and DNA methylation: a review of the interaction between two genomes

2020 ◽  
Vol 12 (1) ◽  
Author(s):  
Amanda F. C. Lopes
Keyword(s):  
Dna Methylation ◽  
Mitochondrial Dysfunction ◽  
Nuclear Dna ◽  
Tricarboxylic Acid Cycle ◽  
Nuclear Gene ◽  
Nuclear Gene Expression ◽  
One Step ◽  
Methionine Pathway ◽  
One Carbon Metabolism ◽  
The One

AbstractMitochondria are controlled by the coordination of two genomes: the mitochondrial and the nuclear DNA. As such, variations in nuclear gene expression as a consequence of mutations and epigenetic modifications can affect mitochondrial functionality. Conversely, the opposite could also be true. However, the relationship between mitochondrial dysfunction and epigenetics, such as nuclear DNA methylation, remains largely unexplored. Mitochondria function as central metabolic hubs controlling some of the main substrates involved in nuclear DNA methylation, via the one carbon metabolism, the tricarboxylic acid cycle and the methionine pathway. Here, we review key findings and highlight new areas of focus, with the ultimate goal of getting one step closer to understanding the genomic effects of mitochondrial dysfunction on nuclear epigenetic landscapes.

Capacité de la méthionine, de la thiamine ou du pantothénate à renverser la toxicité, pour Escherichia coli, d'acides α-aminés artificiels homologues, dont la norleucine; mise en evidence du rôle probable de la méthionine dans la biosynthèse des deux vitamines

1973 ◽  
Vol 51 (5) ◽  
pp. 673-685
Author(s):  
G. Planet ◽  
C. J. Abshire
Keyword(s):  
Escherichia Coli ◽  
Amino Acids ◽  
Chemical Synthesis ◽  
Linear Groups ◽  
Biosynthetic Enzymes ◽  
E Coli ◽  
Mechanism Of Toxicity ◽  
Methionine Pathway

We have previously made the chemical synthesis of artificial α-amino acids substituted by one or two alkylated linear groups on the α-carbon. Our present results indicate that they have a capacity to stop the growth of E. coli 9723. When they have toxicity, the inhibition is competitively reversed by L-methionine and noncompetitively by pantothenate or thiamine; these compounds act as methionine analogues. We have concluded that the mechanism of toxicity is due in part to the repression of biosynthetic enzymes of the methionine pathway and partly to the inhibition of homoserine-O-transsuccinylase, which is the first enzyme of this pathway. We think that the consequence is an intracellular deficiency of methionine which, in turn, causes a lack of pantothenate and thiamine. Our results, therefore, indicate that methionine is necessary for the biosynthesis of pantothenate and thiamine.

scholarly journals Gene Expression in 1-Methylcyclopropene (1-MCP) Treated Tomatoes during Pre-Climacteric Ripening Suggests Shared Regulation of Methionine Biosynthesis, Ethylene Production and Respiration

Agronomy ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1669
Author(s):  
Dan Gamrasni ◽  
Ester Feldmesser ◽  
Ruth Ben-Arie ◽  
Amir Raz ◽  
Amit Tabatznik Asiag ◽  
...  
Keyword(s):  
Gene Expression ◽  
Ethylene Production ◽  
Tomato Fruit ◽  
Binding Motif ◽  
Methionine Biosynthesis ◽  
Climacteric Fruit ◽  
Early Ripening ◽  
Methionine Pathway ◽  
Methionine Synthesis ◽  
Insight Into

The physiology of fruit ripening is defined as either ‘climacteric’ or ‘non-climacteric’. In climacteric fruit respiration during ripening increases until it reaches a peak, which is accompanied by an increase in autocatalytic ethylene production, whereas the respiration of non-climacteric fruit does not increase and they have no requirement for ethylene to complete their ripening. In an attempt to gain further insight into the involvement of autocatalytic ethylene production with the climacteric rise in respiration, tomato fruit were harvested at three defined stages of maturity prior to the climacteric peak (mature green, breaker, and early orange) and immediately exposed to the gaseous molecule 1-methylcyclopropene (1-MCP). The gene expression profile at each of these stages was monitored after 24 h, using an Affymetrix tomato microarray chip. This approach enabled us to identify ethylene responsive genes that are commonly regulated at early stages of ripening, as well as new candidate genes. In addition, 1-MCP treatment affected the levels of metabolites related to methionine biosynthesis. Methionine feeds climacteric ethylene production and we found that promotors of the genes of enzymes that catalyze the production of homoserine and homocysteine (aspartokinase/homoserine dehydrogenases and cystathionine beta lyase, respectively), precursors in the methionine pathway, contain the AtSR1 binding motif. This binding motif is recognized by ethylene activated transcription factors, hence indicating a role for ethylene in methionine synthesis during early ripening, explaining the autocatalytic ethylene production during subsequent ripening stages.

Diminished Pulmonary Lecithin Synthesis in Acidosis: Experimental Findings as Related to the Respiratory Distress Syndrome

PEDIATRICS ◽  
1976 ◽  
Vol 57 (1) ◽  
pp. 32-40
Author(s):  
T. Allen Merritt ◽  
Philip M. Farrell
Keyword(s):  
Respiratory Distress Syndrome ◽  
Respiratory Distress ◽  
Distress Syndrome ◽  
De Novo ◽  
Ph Effects ◽  
Ph Values ◽  
Fetal Rats ◽  
Methionine Pathway ◽  
Experimental Findings

Lung slices from term fetal rats were incubated in vitro at various pH values and the rates of the two de novo pathways for lecithin biosynthesis were determined by measuring the conversion of either 14C-choline (pathway 1) or 14C-methionine (pathway 2) to the phospholipid. It was observed that the choline pathway, but not phosphatidyle-thanolamine methylation, is pH-sensitive with maximum rates occurring at pH levels between 7.3 and 7.5; significantly less activity was found at pH levels between 7.0 and 7.2 and at pH levels between 7.6 and 8.0. Adjustment of the pH from 7.0 to 7.4 in vitro, simulating the clinical correction of acidosis by alkali infusion, was found to increase the conversion of choline to lecithin to a rate approximating that observed at pH 7.4. Since lecithins are the principal phospholipid components of pulmonary surfactant, and since pathway 1 is predominantly responsible for lung lecithin synthesis, the demonstration of impaired production with reduced pH offers a biochemical explanation for the pathophysiological effects of acidosis in the respiratory distress syndrome. A comparison of pH effects on choline pathway rate with the pH profiles of pathway enzymes suggests that these effects are mediated by the catalysts of lecithin synthesis.

scholarly journals Molecular mechanisms of an inborn error of methionine pathway. Methionine adenosyltransferase deficiency.

1995 ◽  
Vol 96 (4) ◽  
pp. 1943-1947 ◽  
Author(s):  
T Ubagai ◽  
K J Lei ◽  
S Huang ◽  
S H Mudd ◽  
H L Levy ◽  
...  
Keyword(s):  
Inborn Error ◽  
Molecular Mechanisms ◽  
Methionine Adenosyltransferase ◽  
Methionine Pathway

scholarly journals Impairment of MET transcriptional activators, MET4 and MET31 induced lipid accumulation in Saccharomyces cerevisiae

2020 ◽  
Vol 20 (5) ◽  
Author(s):  
Selvaraj Rajakumar ◽  
Vennila Suriyagandhi ◽  
Vasanthi Nachiappan
Keyword(s):  
Lipid Accumulation ◽  
Lipid Droplets ◽  
Lipid Homeostasis ◽  
Transcriptional Activators ◽  
Wild Type ◽  
Concomitant Increase ◽  
Lipid Profiling ◽  
Sterol Esters ◽  
Methionine Pathway ◽  
The Impact

ABSTRACT The genes involved in the methionine pathway are closely associated with phospholipid homeostasis in yeast. The impact of the deletion of methionine (MET) transcriptional activators (MET31, MET32 and MET4) in lipid homeostasis is studied. Our lipid profiling data showed that aberrant phospholipid and neutral lipid accumulation occurred in met31∆ and met4∆ strains with low Met. The expression pattern of phospholipid biosynthetic genes such as CHO2, OPI3 and triacylglycerol (TAG) biosynthetic gene, DGA1 were upregulated in met31∆, and met4∆ strains when compared to wild type (WT). The accumulation of triacylglycerol and sterol esters (SE) content supports the concomitant increase in lipid droplets in met31∆ and met4∆ strains. However, excessive supplies of methionine (1 mM) in the cells lacking the MET transcriptional activators MET31 and MET4 ameliorates the abnormal lipogenesis and causes aberrant lipid accumulation. These findings implicate the methionine accessibility plays a pivotal role in lipid metabolism in the yeast model.

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