Recombinant Human TPST1 Protein, CF

Tyrosine O-sulfation is a posttranslational modification of proteins in all multicellular organisms. This reaction is mediated by a Golgi enzyme activity called Tyrosylprotein Sulfotransferase (TPST) that transfers sulfate from 3'-phosphoadenosine 5'-phosphosulfate (PAPS) to tyrosine residues within acidic motifs of polypeptides to form tyrosine O-sulfate ester (1). More than 60 proteins have been identified to be tyrosine sulfated, for some of which the functions have been identified. For example, sulfation of tyrosine residues in the leukocyte adhesion molecule P-selectin glycoprotein ligand 1 (PSGL-1) is required for binding to P-selectin on activated endothelium (2, 3). Tyrosine sulfation of chemokine receptors CCR5 and CXCR4 have been reported to facilitate HIV-1 entry of target cells (4, 5). Two TPSTs with overlapping substrate specificities are found in the human genome. TPST1 is widely expressed in all major tissues. The TPST1 knock-out mice showed phenotype of reduced body weight and increased postimplantation fetal death (6).