Kinase that plays a key role in regulation of glucose and fatty acid metabolism and homeostasis via phosphorylation of the pyruvate dehydrogenase subunits PDHA1 and PDHA2 (PubMed:7499431, PubMed:18541534, PubMed:22195962, PubMed:26942675, PubMed:17683942). This inhibits pyruvate dehydrogenase activity, and thereby regulates metabolite flux through the tricarboxylic acid cycle, down-regulates aerobic respiration and inhibits the formation of acetyl-coenzyme A from pyruvate (PubMed:18541534, PubMed:22195962, PubMed:26942675). Plays an important role in cellular responses to hypoxia and is important for cell proliferation under hypoxia (PubMed:18541534, PubMed:22195962, PubMed:26942675). {ECO:0000269|PubMed:17683942, ECO:0000269|PubMed:18541534, ECO:0000269|PubMed:22195962, ECO:0000269|PubMed:26942675, ECO:0000269|PubMed:7499431}. This is the function of Ensembl gene identifier ENSG00000152256 (PDK1, pyruvate dehydrogenase kinase 1).