is a posttranslational modification
where a sulfate
group is added to a tyrosine
residue of a protein molecule. Secreted proteins and extracellular parts of membrane proteins that pass through the Golgi apparatus
may be sulfated. Sulfation was first discovered by Bettelheim
in bovine fibrinopeptide B in 1954 and later found be present in animals and plants but not in prokaryotes
or in yeast.
Sulfation plays role in strengthening protein-protein interactions. Types of human proteins known to undergo tyrosine sulfation include adhesion molecules, G-protein-coupled receptors, coagulation factors, serine protease inhibitors
, extracellular matrix proteins, and hormones.Tyrosine O-sulfate is a stable molecule and is excreted in urine in animals. No enzymatic mechanism of tyrosine sulfate desulfation is known to exist.
By knock-out of TPST genes in mice, it may be observed that tyrosine sulfation has effects on the growth of the mice, such as body weight, fecundity, and postnatal viability.
Sulfation is catalyzed by tyrosylprotein sulfotransferase
(TPST) in Golgi apparatus
. The reaction catalyzed by TPST is a transfer of sulfate from the universal sulfate donor 3'-Phosphoadenosine-5'-phosphosulfate
(PAPS) to the side-chain hydroxyl group of a tyrosine residue. Sulfation sites are tyrosine residues... Read More