High impact information on PDK

• Pyruvate dehydrogenase kinase from Arabidopsis thaliana: a protein histidine kinase that phosphorylates serine residues [1].
• Pyruvate dehydrogenase kinase (PDHK), a negative regulator of the mitochondrial pyruvate dehydrogenase (PDH) complex (mtPDC), plays a pivotal role in controlling mtPDC activity, and hence, the TCA cycle and cell respiration [2].
• This report describes the cloning of a pyruvate dehydrogenase kinase cDNA (AtPDHK) from Arabidopsis thaliana and focuses on the effects of antisense down-regulation of its expression on plant growth and development [2].
• The pH dependence of k(cat) of Arabidopsis thaliana PDK indicates that ionizable groups with pK values of 6.2 and 8.4 are necessary for catalysis, and the temperature dependence of these values suggests that the acidic pK is due to a carboxyl- or imidazole-group [3].
• Previously, the cloning of a PDHK cDNA from Arabidopsis thaliana and the effects of constitutively down-regulating its expression on plant growth and development has been reported [4].

Biological context of PDK

• Histidine mutagenesis of Arabidopsis thaliana pyruvate dehydrogenase kinase [5].

Associations of PDK with chemical compounds

• Histidine modifying agents abolish pyruvate dehydrogenase kinase activity [6].
• These findings suggest that a partial reduction of the repression of the mtPDC by antisense PDHK expression can alter carbon flux and, in particular, the contribution of carbon moieties from pyruvate to fatty acid biosynthesis and storage lipid accumulation in developing seeds, implicating a role for mtPDC in fatty acid biosynthesis in seeds [4].

References