MPST
Description
The MPST (mercaptopyruvate sulfurtransferase) is a protein-coding gene located on chromosome 22.
MPST, encoded by the MPST gene, is a 3-mercaptopyruvate sulfurtransferase (EC 2.8.1.2) that catalyzes the chemical reactions of 3-mercaptopyruvate. It is a member of the transferase family, specifically the sulfurtransferases, and is involved in cysteine metabolism. The enzyme is of particular interest for its role in cyanide detoxification due to its widespread presence in the cytosol. The MPST gene is located on chromosome 22q12.3 and consists of 6 exons. Alternative splicing generates different transcript variants that encode the same protein. MPST is a cytoplasmic protein belonging to the rhodanese family but is not rhodanese itself, which is found only in mitochondria.
MPST catalyzes the transfer of a sulfur ion to cyanide or other thiol compounds. It exhibits weak rhodanese activity and plays a crucial role in detoxifying cyanide. MPST is essential for thiosulfate biosynthesis and acts as an antioxidant. In collaboration with cysteine aminotransferase (CAT), it contributes to the breakdown of cysteine and is a significant producer of hydrogen sulfide (H2S) in the brain, retina, and vascular endothelial cells. H2S is a critical synaptic modulator, signaling molecule, smooth muscle contractor, and neuroprotectant. The production of H2S by the MPST/CAT pathway is regulated by calcium ions.
MPST is also known as MST, TST2, TUM1.
