Tyrosine sulfation
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 was first discovered by Bettelheim in bovine fibrinopeptide B in 1954 and later found be present in animals and plants but not in prokaryote
s or in yeast.
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.
(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 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)http://www.expasy.org/cgi-bin/nicedoc.pl?PS00003. Two types of tyrosylprotein sulftotransferases (TPST-1 and TPST2) have been identified.
describing the production and characterization of an antibody
called PSG2. This antibody shows exquisite sensitivity and specificity for epitopes containing sulfotyrosine independent of the sequence context.
Posttranslational modification
Posttranslational modification is the chemical modification of a protein after its translation. It is one of the later steps in protein biosynthesis, and thus gene expression, for many proteins....
where a sulfate
Sulfate
In inorganic chemistry, a sulfate is a salt of sulfuric acid.-Chemical properties:...
group is added to a tyrosine
Tyrosine
Tyrosine or 4-hydroxyphenylalanine, is one of the 22 amino acids that are used by cells to synthesize proteins. Its codons are UAC and UAU. It is a non-essential amino acid with a polar side group...
residue of a protein molecule. Secreted proteins and extracellular parts of membrane proteins that pass through the Golgi apparatus
Golgi apparatus
The Golgi apparatus is an organelle found in most eukaryotic cells. It was identified in 1898 by the Italian physician Camillo Golgi, after whom the Golgi apparatus is named....
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 prokaryote
Prokaryote
The prokaryotes are a group of organisms that lack a cell nucleus , or any other membrane-bound organelles. The organisms that have a cell nucleus are called eukaryotes. Most prokaryotes are unicellular, but a few such as myxobacteria have multicellular stages in their life cycles...
s or in yeast.
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.
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.
Mechanism
Sulfation is catalyzed by tyrosylprotein sulfotransferaseTyrosylprotein sulfotransferase
Tyrosylprotein sulfotransferase is an enzyme that catalyzes tyrosine sulfation.- Examples :Human genes that encode protein-tyrosine sulfotransferase enzymes include:...
(TPST) in Golgi apparatus
Golgi apparatus
The Golgi apparatus is an organelle found in most eukaryotic cells. It was identified in 1898 by the Italian physician Camillo Golgi, after whom the Golgi apparatus is named....
. The reaction catalyzed by TPST is a transfer of sulfate from the universal sulfate donor 3'-phosphoadenosine-5'-phosphosulfate
3'-Phosphoadenosine-5'-phosphosulfate
3'-Phosphoadenosine-5'-phosphosulfate is a derivative of adenosine monophosphate that is phosphorylated at the 3' position and has a sulfate group attached to the 5' phosphate. This anion, abbreviated PAPS, serves as a coenzyme in sulfotransferase reactions...
(PAPS) to the side-chain hydroxyl group of a tyrosine residue. Sulfation sites are 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)http://www.expasy.org/cgi-bin/nicedoc.pl?PS00003. Two types of tyrosylprotein sulftotransferases (TPST-1 and TPST2) have been identified.
Regulation
There is very limited evidence that the TPST genes are subject to transcriptional regulation and tyrosine O-sulfate is very stable and cannot be easily degraded by mammalian sulfatases. Tyrosine O-sulfation is an irreversible process in vivo.Antibody for detection of tyrosine-sulfated epitopes
In 2006, an article was published in the Journal of Biological ChemistryJournal of Biological Chemistry
The Journal of Biological Chemistry is a weekly peer-reviewed scientific journal that was established in 1905. Since 1925 it is published by the American Society for Biochemistry and Molecular Biology. It covers research in any area of biochemistry or molecular biology. The editor-in-chief is...
describing the production and characterization of an antibody
Antibody
An antibody, also known as an immunoglobulin, is a large Y-shaped protein used by the immune system to identify and neutralize foreign objects such as bacteria and viruses. The antibody recognizes a unique part of the foreign target, termed an antigen...
called PSG2. This antibody shows exquisite sensitivity and specificity for epitopes containing sulfotyrosine independent of the sequence context.