Importance and mechanisms of S-adenosylmethionine and folate accumulation in sake yeast.

Sake yeasts have a range of brewing characteristics that are particularly beneficial for sake making including high ethanol fermentability, high proliferative capacity at low temperatures, lactic acid tolerance, and high ester productivity. On the other hand, sake yeasts also accumulate a diverse range of functional components. For example, significantly greater accumulation of S-adenosylmethionine (SAM), a compound that plays important regulatory roles in a range of biological processes as a major donor of methyl groups, occurs in sake yeasts compared to other microorganisms.

The sake yeast allele contributes to the regulation of the tetrahydrofolate content in the folate synthetic pathway in sake yeast strains.

To elucidate the mechanism underlying tetrahydrofolate (THF) accumulation in sake yeast strains compared with that in laboratory yeast strains, we performed a quantitative trait locus (QTL) analysis. The results revealed that the sake yeast allele contributes to an increase in the ratio of THF to the total folate content in sake yeast.

Breeding of a cordycepin-resistant and adenosine kinase-deficient sake yeast strain that accumulates high levels of -adenosylmethionine.

Adenosine kinase ()-deficient mutants can be obtained from cordycepin-resistant strains, and the disruption of causes -adenosylmethionine (SAM) accumulation. To breed a high-SAM-accumulating yeast strain without genetic manipulation for industrial purposes, we bred a cordycepin-resistant strain using sake yeast kyokai No. 9 as the parent strain with a mutation in adenosine kinase () and acquired high-SAM-accumulating strain.

A genetic method to enhance the accumulation of S-adenosylmethionine in yeast.

S-Adenosylmethionine (SAM) is a key component of sulphur amino acid metabolism in living organisms and is synthesised from methionine and adenosine triphosphate by methionine adenosyltransferase. This molecule serves as the main biological methyl donor due to its active methylthio ether group. Notably, SAM has shown beneficial effects in clinical trials for the treatment of alcoholic liver disease, depression and joint pain.

Stimulating S-adenosyl-l-methionine synthesis extends lifespan via activation of AMPK.

Dietary restriction (DR), such as calorie restriction (CR) or methionine (Met) restriction, extends the lifespan of diverse model organisms. Although studies have identified several metabolites that contribute to the beneficial effects of DR, the molecular mechanism underlying the key metabolites responsible for DR regimens is not fully understood. Here we show that stimulating S-adenosyl-l-methionine (AdoMet) synthesis extended the lifespan of the budding yeast Saccharomyces cerevisiae The AdoMet synthesis-mediated beneficial metabolic effects, which resulted from consuming both Met and ATP, mimicked CR.