Tyrosine sulfation
From Wikipedia, the free encyclopedia
Tyrosine sulfation 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 is known to happen in animals and plants.
[edit] Function
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.
[edit] Mechanism
Sulfation is catalyzed by tyrosylprotein sulfotransferases (TPSTs) in Golgi apparatus. The reaction catalyzed by TPSTs is a transfer of sulfate from the universal sulfate donor 3'-phosphoadenosine 5'-phosphosulfate to the side-chain hydroxyl group of a tyrosine residue. Sulfation sites are have a tyrosine residues exposed on the surface of the protein typically surrounded by acidic residues, a detailed description of the characteristics of the sulfation site is available from PROSITE (PROSITE pattern: PS00003)[1]. Two types of tyrosylprotein sulftotransferases (TPST-1 and TPST2) have been identified.
[edit] References
Moore KL. The biology and enzymology of protein tyrosine O-sulfation. J Biol Chem, 278:24243-24246. 2003. [2]
