Disease relevance of TPS2

• The Escherichia coli otsBA operon, located at min 42, was sequenced and shown to encode a 29.1-kDa trehalose-6-phosphate phosphatase (OtsB) and a 53.6-kDa trehalose-6-phosphate synthase (OtsA) [1].
• Results indicated that washing the skin in mixtures of TPP and fatty acids produced significant reductions in the number of aerobic bacteria, campylobacters, E. coli, pseudomonads, and yeasts recovered from skin rinsates, but there was no significant reduction in the populations of enterococci, lactic acid bacteria, or staphylococci [2].
• Results indicated that TPP solutions are highly bactericidal toward gram-negative bacteria and that mixtures of TPP and fatty acids are highly microbicidal toward gram-negative bacteria, gram-positive bacteria, and yeasts [2].

High impact information on TPS2

• One such mutation was further characterized and the affected gene was shown to be identical to TPS2 which encodes trehalose phosphate phosphatase, an enzyme catalysing the second step in trehalose biosynthesis [3].
• The marked phenotype obtained of plants accumulating T6P is opposite to that of plants with low T6P levels obtained by expressing either TPP or TPH and consistent with a critical role for T6P in growth and development [4].
• Since we observed measurable trehalose in strains lacking all but the TPS1 gene, some phosphatase activity in addition to Tps2 can hydrolyze trehalose 6-phosphate [5].
• The TPS2 promoter contains four STREs that may mediate dihydrosphingosine responsiveness [6].
• Synthesis of trehalose in the yeast Saccharomyces cerevisiae is catalysed by the trehalose-6-phosphate (Tre6P) synthase/phosphatase complex, which is composed of at least three different subunits encoded by the genes TPS1, TPS2, and TSL1 [7].

Chemical compound and disease context of TPS2

• None of the sequences was similar to the E1 component of pyruvate dehydrogenase from E. coli which also decarboxylates pyruvate with the help of TPP [8].
• Skin samples were washed in mixtures of TPP and fatty acid, and the populations of total aerobic bacteria, campylobacters, enterococci, E. coli, lactic acid bacteria, pseudomonads, staphylococci, and yeasts in the skin rinsates were enumerated on the appropriate microbiological media [2].

Biological context of TPS2

• However, accumulation of trehalose-6-phosphate did cause some phenotypes in the tps2 mutant, such as temperature sensitivity for growth [9].
• The amino acid sequence encoded by ZrTPS1 has relatively high homology with TPS1 of Saccharomyces cerevisiae and Schizosaccharomyces pombe, compared with TPS2 [10].
• Based on EST (expressed sequence tag) sequences, three full-length Arabidopsis cDNAs whose predicted protein sequences show extensive homologies to known TPS and TPP proteins were amplified by RACE-PCR [11].
• An orlA1 complementing fragment from the cosmid was sequenced. orlA encodes a predicted polypeptide of 227 amino acids (26360 Da) that is homologous to a 211-amino-acid domain from the polypeptide encoded by the Saccharomyces cerevisiae TPS2 gene and to almost the entire Escherichia coli otsB-encoded polypeptide [12].
• Partial DNA sequence shows that PFK3 is identical to TPS2 (De Virgilio et al., 1993) [13].

Anatomical context of TPS2

• Inhibition of hexokinase activity by Tre6P is less efficiently counteracted by glucose in permeabilized spheroplasts compared to cell extracts, and this effect is largely abolished by deletion of TPS2 but not TPS1 [14].
• After 8 days, the level of TPP in the erythrocytes of deficient animals was 10% of the level in pair-fed controls [15].

Associations of TPS2 with chemical compounds

• The byp 1-3 tps2 delta double mutant showed elevated tre-6-P levels along with improved growth and ethanol production, although the estimated concentrations of glycolytic metabolites indicated excessive sugar influx [16].
• Thiamin pyrophosphate (TPP) is a coenzyme derived from vitamin B1 (thiamin) [17].
• TPP is essential for central metabolic processes, including the formation of acetyl CoA from glucose and the Krebs cycle [17].
• In other TPP-utilizing enzymes, the equivalent residue of Q428 is a histidine and is thought to deprotonate the 4'-amino group [18].
• 31P NMR studies with PDC in the presence of added Mn2+ reveal the pyrophosphate moiety of TPP to be a nonaccessible area for the external Mn2+ and thus proving the Mg-P-complex (taking part in the binding of the coenzyme to the protein) to be a nonaccessible area for the medium [19].

Physical interactions of TPS2

• When the temperature of exponential-phase cultures of Saccharomyces cerevisiae was abruptly raised from 28 to 40 degrees C, trehalose immediately accumulated, whereas the activities of trehalase and trehalose-6-phosphate synthase/trehalose-6-phosphate phosphatase complex increased after a lag period of about 10 min [20].

Other interactions of TPS2

• Gene disruptions showed that tps2 and hsp104 null mutants each produced moderate heat shock sensitivity in stationary phase cells [9].
• Finally, we isolated a high copy number suppressor of the temperature sensitivity of tps2, which we call PMU1, which reduced the levels of trehalose-6-phosphate in tps2 mutants [9].
• Analysis of PFK3--a gene involved in particulate phosphofructokinase synthesis reveals additional functions of TPS2 in Saccharomyces cerevisiae [13].

Analytical, diagnostic and therapeutic context of TPS2

• Glyoxylic acid, acting as an inhibitor of PDC by forming a noncleavable bond with the catalytic center of TPP causes a steric immobilization of the coenzyme indicated by a line broadening of the pyrophosphate moiety [19].

References