UDP-glucuronosyltransferase 2B4 (UGT2B4) and Sulfotransferase 2A1 (SULT2A1) (UGT2B4 and SULT2A1)

UDP-glucuronosyltransferase 2B4 (UGT2B4) and Sulfotransferase 2A1 (SULT2A1) are critical Phase II drug-metabolizing enzymes primarily located in the liver that work in tandem to detoxify bile acids and endogenous steroids (UniProt, 2023). UGT2B4 is responsible for the glucuronidation of bile acids like hyodeoxycholic acid, while SULT2A1 is the major enzyme for the sulfation of dehydroepiandrosterone (DHEA) and various bile acid species (PubMed, 2021). These conjugation reactions increase the hydrophilicity of substrates, facilitating their excretion via the kidneys or bile and preventing the accumulation of toxic hydrophobic bile acids. In diseases such as primary biliary cholangitis (PBC) and non-alcoholic steatohepatitis (NASH), these enzymes are often downregulated or overwhelmed, leading to hepatotoxicity. Pharmacological agents like obeticholic acid act as agonists of the Farnesoid X Receptor (FXR), which directly induces the expression of both UGT2B4 and SULT2A1 to restore bile acid homeostasis (NIH, 2022). Understanding the combined activity of these enzymes is essential for managing cholestatic conditions and predicting potential drug-drug interactions involving Phase II metabolic pathways.

Other names

UDPGT 2B4HLUG25UDP-glucuronosyltransferase 2B4Dehydroepiandrosterone sulfotransferaseDHEA-STST2A1STDhSTaAlcohol sulfotransferaseBile salt sulfotransferase

Transcriptional induction via activation of the Farnesoid X Receptor (FXR) to increase the glucuronidation and sulfation of bile acids, thereby promoting their metabolic clearance and detoxification.