PCK1 Antibody (YA242),MedChemexpress,HY-P80267

PCK1 is a cytosolic phosphoenolpyruvate carboxykinase that catalyzes the reversible decarboxylation and phosphorylation of oxaloacetate (OAA) and serves as the rate-limiting enzyme in gluconeogenesis. It regulates cataplerosis and anaplerosis, processes that control the levels of metabolic intermediates in the citric acid cycle. At low glucose levels, PCK1 catalyzes the cataplerotic conversion of oxaloacetate to phosphoenolpyruvate (PEP), the rate-limiting step in the metabolic pathway producing glucose from lactate and other citric acid cycle-derived precursors. At high glucose levels, it catalyzes the anaplerotic conversion of phosphoenolpyruvate to oxaloacetate. PCK1 also acts as a regulator of memory CD8(+) T-cell formation and maintenance: it is up-regulated in these cells, generating phosphoenolpyruvate via gluconeogenesis (By similarity). The resulting phosphoenolpyruvate flows into glycogen and the pentose phosphate pathway, essential for memory CD8(+) T-cell homeostasis (By similarity). Beyond its phosphoenolpyruvate carboxykinase activity, PCK1 functions as a protein kinase when phosphorylated at Ser-90: phosphorylation by AKT1 reduces oxaloacetate binding affinity and promotes an atypical serine protein kinase activity using GTP as a donor. This kinase activity regulates lipogenesis: upon Ser-90 phosphorylation, PCK1 translocates to the endoplasmic reticulum and phosphorylates INSIG proteins (INSIG1 and INSIG2), disrupting their interaction with SCAP and promoting nuclear translocation of SREBP proteins (SREBF1/SREBP1 or SREBF2/SREBP2), leading to transcription of lipogenesis-related genes.