High impact information on PDC2

• PET100 is located adjacent to the PDC2 gene on chromosome IV and contains an open reading frame of 333 base pairs [1].
• In this yeast THI regulatory system acts mainly at the transcriptional level, thiamin pyrophosphate (TDP) seems to serve as a corepressor, and genetic studies have identified three positive regulatory factors (Thi2p, Thi3p and Pdc2p) [2].
• From the nucleotide sequence of the cloned DNA, which contained an open reading frame of 765 codons, the predicted protein is 49.5% identical to the Pdc2 protein of Saccharomyces cerevisiae, a regulator of pyruvate decarboxylase in this yeast [3].
• All the three suppressors suppress pdc2 delta as well and act on PDC1 at the level of transcription [4].
• Suppression of pdc2 regulating pyruvate decarboxylase synthesis in yeast [4].

Biological context of PDC2

• Both are known to affect gene expression in an autoregulatory mechanism and expression of both is regulated by glucose and Pdc2, further pointing to a role of Pdc2 in coordinating different metabolic signals [5].
• Using global and gene-specific expression analysis, we show that Pdc2 is required for the upregulation of all genes controlled by thiamine availability [5].
• The PDC2 deletion mutant exhibits a phenotype very similar to, but more severe than that of the point mutant: a strongly reduced pyruvate decarboxylase specific activity, slow, respiration-dependent growth on glucose, and accumulation of pyruvate [6].
• The amino acid sequence comparisons between CaPdc2p of C. albicans and both Pdc2p of Saccharomyces cerevisiae and Rag3p of Kluyveromyces lactis, revealed similarities of 40% and 39%, respectively [7].

Associations of PDC2 with chemical compounds

• The Pdc2 has also been implicated as a regulator of genes encoding enzymes in ThDP metabolism [5].
• Synthesis of pyruvate decarboxylase is regulated by PDC2 at the transcriptional level [6].

Regulatory relationships of PDC2

• Thus, PDC2 is either important for a high basal level of PDC gene expression or it plays a positive role in the autoregulation that controls expression of PDC1 and PDC5 [6].

Other interactions of PDC2

• The DNA binding protein Pdc2 was initially identified as a regulator of the genes PDC1 and PDC5, which encode isoforms of the glycolytic enzyme pyruvate decarboxylase (Pdc) [5].
• The Pdc2 seems to act together with Thi2, a known transcriptional regulator of THI genes [5].
• While the Thi2, in conjunction with Thi3, seems to control expression of THI genes with respect to thiamine availability, the Pdc2 may link the ThDP demand to carbon source availability [5].
• In fact, the triple mutant gpp1 Delta gpp2 Delta pdc2 Delta overexpressing GPD1 accumulated 17 mg L-G3P/g dry weight during glucose batch fermentation under oxygen limitation [8].

References