Possible regulation of trehalose metabolism by methylation in Saccharomyces cerevisiae

Abstract

The current study was undertaken to correlate post-translational protein modification by methylation with the functionality of enzymes involved in trehalose metabolism in Saccharomyces cerevisiae. Trehalose is an economically important disaccharide providing protection against various kinds of stresses. It also acts as a source of cellular energy by storing glucose. Methyl group donor S-adenosyl L-methionine (AdoMet) and methylation inhibitor-oxidized adenosine (AdOx) were used for the methylation study. AdoMet delayed initial growth of the cells but the overall growth rate remained same suggesting its interference in G1 phase of the cell cycle. Metabolic-altered enzyme activities of acid trehalase (AT), neutral trehalase (NT), and trehalose-6-phosphate synthase (TPS) were observed when treated with AdOx and AdoMet separately. A positive effect of methylation was observed in TPS, hence, it was purified in three different conditions, using AdoMet, AdOx, and control. Differences in mobility of methylated, methylation-inhibited, and control TPS during acidic native gel electrophoresis confirmed the occurrence of induced methylation. Hydrolysis under alkaline pH conditions revealed that methylation of TPS was different than O-methylation. MALDI-TOF analysis of trypsin-digested samples of purified methylated, methylation-inhibited, and control TPS revealed that an increase of 18 Da mass in methylated peptides suggesting the introduction of methyl ester in TPS. Results of amino acid analysis corroborated the presence of methyl cysteine. The data presented here strongly suggests that trehalose production was enhanced due to methylation of TPS arising from carboxymethylation of cysteine residues.

The importance of post-translational modifications in regulating Saccharomyces cerevisiae metabolism

“…So far, the acetylproteome of S. cerevisiae has not been analyzed, but several lines of evidence suggest that the extent and relevance of protein acetylation in regulating yeast metabolism may be akin to S. enterica and mammalian cells (Lin et al, 2008(Lin et al, , 2009. The role of methylation in modulating yeast metabolic activity has been, indeed, only documented for three enzymes involved in trehalose metabolism (Sengupta et al, 2011). Among these, they detected acetylation in the gluconeogenic enzyme phosphoenolpyruvate carboxykinase (Pck1) and verified that acetylation of Pck1 at Lys514 is required to assure maximal enzyme activity.…”

“…N-methylation is a frequent, irreversible PTM modifying mainly histones and proteins involved in translational processes (Walsh et al, 2005;Walsh, 2006), though it has not been found to impact metabolic enzymes post-translationally (Pang et al, 2010). The role of methylation in modulating yeast metabolic activity has been, indeed, only documented for three enzymes involved in trehalose metabolism (Sengupta et al, 2011). In their study, they showed that trehalose synthase (Tps1) is subjected to S-methylation in a cysteine residue by formation of a thiol ester, which enhances Tps1 activity.…”

Trehalose metabolism genes render rice white tip nematode, Aphelenchoides besseyi (Nematoda: Aphelenchoididae) resistant to anaerobic environment

“…To date, no TPP gene or domain has been identified in nematodes; it is possible that nematodes may synthesize endogenous trehalose using unspecific phosphatases ( Sengupta et al, 2011a , b ; Hespeels et al, 2015 ). Trehalose is suggested to be a signalling molecule, as well as a bioprotective molecule ( Hespeels et al, 2015 ).…”

“…In most eukaryotes, trehalose is catalysed by three trehalose metabolism enzymes. Trehalose-6-phosphate synthase (TPS) ( Vandesteene et al, 2010 ; Li et al, 2011 ; Sengupta et al, 2011a , b ; Delorge et al, 2015 ) and trehalose-6-phosphate phosphatase (TPP) ( Ponnu et al, 2011 ; Vandesteene et al, 2012 ; Lahiri et al, 2014 ; Yadav et al, 2014 ) are responsible for trehalose synthesis ( Avonce et al, 2010 ); trehalase (TRE) catalyses the hydrolysis of trehalose ( Pellerone et al, 2003 ; Hespeels et al, 2015 ), and regulates the concentration of sugars ( Alabran et al, 1983 ; Behm, 1997 ). It has been reported that trehalose hydrolysis is catalysed by two types of TRE, acid TRE (AT; Dmitryjuk and Zółtowska, 2003 ) and neutral TRE (NT; Londesborough and Varimo, 1984 ).…”

“…As the only hydrolase that specifically hydrolyses trehalose into glucose, TRE is proposed to be the key enzyme of trehalose metabolism ( Dmitryjuk et al, 2006 ). Based on research into the function of different types of TRE ( Alabran et al, 1983 ; Sengupta et al, 2011a , b ; Van Houtte et al, 2013 ), as well as the research and application of enzyme inhibitors, TRE has become a new potential target of plant parasitic nematode control. A correlation between regulation of trehalose synthesis and survivability of the organism under thermal stress has been established in Candida utilis ( Lahiri et al, 2014 ).…”