MPST

This protein encoded by this gene catalyzes the transfer of a sulfur ion from 3-mercaptopyruvate to cyanide or other thiol compounds. It may be involved in cysteine degradation and cyanide detoxification. There is confusion in literature between this protein (mercaptopyruvate sulfurtransferase, MPST), which appears to be cytoplasmic, and thiosulfate sulfurtransferase (rhodanese, TST, GeneID:7263), which is a mitochondrial protein. Deficiency in MPST activity has been implicated in a rare inheritable disorder known as mercaptolactate-cysteine disulfiduria (MCDU). Alternatively spliced transcript variants encoding same or different isoforms have been identified for this gene. [provided by RefSeq]

Full Name

mercaptopyruvate sulfurtransferase

Function

Transfer of a sulfur ion to cyanide or to other thiol compounds. Also has weak rhodanese activity. Detoxifies cyanide and is required for thiosulfate biosynthesis. Acts as an antioxidant. In combination with cysteine aminotransferase (CAT), contributes to the catabolism of cysteine and is an important producer of hydrogen sulfide in the brain, retina and vascular endothelial cells. Hydrogen sulfide H2S is an important synaptic modulator, signaling molecule, smooth muscle contractor and neuroprotectant. Its production by the 3MST/CAT pathway is regulated by calcium ions.

Biological Process

Cyanate catabolic process Source: ProtInc
Hydrogen sulfide biosynthetic process Source: UniProtKB
Kidney development Source: Ensembl
Liver development Source: Ensembl
Response to toxic substance Source: ProtInc
Spinal cord development Source: Ensembl
Sulfur amino acid catabolic process Source: Reactome
Transsulfuration Source: GO_Central

Cellular Location

Mitochondrion
Cytoplasm By similarity
Other locations
synaptosome

Involvement in disease

Aberrant MPST activity is found in a few cases of mercaptolactate-cysteine disulfiduria (MCDU) characterized by the appearance of large quantaties of the sulfur-containing amino acid, beta-mercaptolactate-cysteine disulfide, in the urine (PubMed:4973015, PubMed:4690911 and PubMed:6945862). Some cases have associated mental retardation (PubMed:4973015 and PubMed:6945862).