Citrate (CIT)

Citrate is a central metabolic intermediate and signaling molecule that plays a pivotal role in cellular energy homeostasis and de novo lipogenesis. Produced within the mitochondria as part of the tricarboxylic acid (TCA) cycle, it is exported to the cytosol via the mitochondrial citrate carrier (SLC25A1), where it serves as a substrate for ATP-citrate lyase (ACLY) to produce acetyl-CoA for fatty acid and cholesterol synthesis. Beyond its metabolic role, citrate acts as a potent allosteric modulator of key regulatory enzymes, most notably inhibiting phosphofructokinase-1 (PFK-1) to suppress glycolysis and activating acetyl-CoA carboxylase (ACC) to promote lipid synthesis. In oncology, the 'citrate strategy' involves modulating cellular citrate levels—either by inhibiting its transport and metabolism or by administering high-dose exogenous citrate—to disrupt the Warburg effect and induce apoptosis in cancer cells. Clinically, citrate is widely utilized as a pharmacological agent for urinary alkalinization to manage nephrolithiasis and as an anticoagulant in blood storage due to its high affinity for calcium ions. Recent evidence also suggests that citrate levels are critical for bone mineralization and serve as a prognostic biomarker for various metabolic and malignant conditions.

Other names

Citric acidCitrate anion2-hydroxypropane-1,2,3-tricarboxylateCitrate(3-)

Citrate acts as a systemic and urinary alkalinizer by providing bicarbonate equivalents upon metabolic oxidation, which increases urine pH and reduces the crystallization of calcium and uric acid. It functions as a potent allosteric inhibitor of phosphofructokinase-1 (PFK-1) and phosphofructokinase-2 (PFK-2), thereby suppressing glycolysis and regulating metabolic flux. Furthermore, it serves as the primary cytosolic precursor for acetyl-CoA via cleavage by ATP-citrate lyase (ACLY), supporting lipid synthesis and histone acetylation. Pharmacologically, its levels are modulated by targeting transporters such as SLC13A5 and enzymes like ACLY to treat metabolic diseases and cancer.