Nutrient and hormonal regulation of pyruvate kinase gene expression

• DOI: 10.1042/bj3370001
• Publication Date: 2015-08-10T22:04:34Z
• Authors: Kazuya YAMADA; Tamio NOGUCHI
• Keywords: Dephosphorylation

Mammalian pyruvate kinase (PK), a key glycolytic enzyme, has two genes named PKL and PKM, which produce the L- R-type isoenzymes by means of alternative promoters, M1-and M2-types mutually exclusive splicing respectively. The expression these is tissue-specific under developmental, dietary hormonal control. L-type isoenzyme (L-PK) gene contains multiple regulatory elements necessary for regulation in 5' flanking region, up to position -170. Both L-II L-III are required stimulation L-PK transcription carbohydrates such as glucose fructose, although element itself responsive carbohydrates. also responsible polyunsaturated fatty acids. Nuclear factor-1 proteins hepatocyte nuclear factor 4, bind element, may be involved carbohydrate acid However, L-III-element-binding protein that remains clarified, involvement an upstream stimulating been proposed. Available evidence suggests signalling pathway includes metabolite, possibly 6-phosphate or xylulose 5-phosphate, well phosphorylation dephosphorylation mechanisms. In addition, at least five have identified region PKM -279. Sp1-family proximal elements, but binding other not yet clarified. Glucose stimulate via hexosamine derivatives. Sp1 this its dephosphorylation, response determined precisely gene. Thus stimulates mechanism probably different from