Publications

• Identification of tyrosylprotein sulfotransferase in Arabidopsis.

  Komori R., Amano Y., Ogawa-Ohnishi M., Matsubayashi Y.

  Tyrosine sulfation is a posttranslational modification common in peptides and proteins synthesized by the secretory pathway in most eukaryotes. In plants, this modification is critical for the biological activities of a subset of peptide hormones such as PSK and PSY1. In animals, tyrosine sulfatio ... >> More

  Tyrosine sulfation is a posttranslational modification common in peptides and proteins synthesized by the secretory pathway in most eukaryotes. In plants, this modification is critical for the biological activities of a subset of peptide hormones such as PSK and PSY1. In animals, tyrosine sulfation is catalyzed by Golgi-localized type II transmembrane proteins called tyrosylprotein sulfotransferases (TPSTs). However, no orthologs of animal TPST genes have been found in plants, suggesting that plants have evolved plant-specific TPSTs structurally distinct from their animal counterparts. To investigate the mechanisms of tyrosine sulfation in plants, we purified TPST activity from microsomal fractions of Arabidopsis MM2d cells, and identified a 62-kDa protein that specifically interacts with the sulfation motif of PSY1 precursor peptide. This protein is a 500-aa type I transmembrane protein that shows no sequence similarity to animal TPSTs. A recombinant version of this protein expressed in yeast catalyzed tyrosine sulfation of both PSY1 and PSK precursor polypeptide in vitro, indicating that the newly identified protein is indeed an Arabidopsis (At)TPST. AtTPST is expressed throughout the plant body, and the highest levels of expression are in the root apical meristem. A loss-of-function mutant of AtTPST displayed a marked dwarf phenotype accompanied by stunted roots, pale green leaves, reduction in higher order veins, early senescence, and a reduced number of flowers and siliques. Our results indicate that plants and animals independently acquired tyrosine sulfation enzymes through convergent evolution. << Less

  Proc. Natl. Acad. Sci. U.S.A. 106:15067-15072(2009) [PubMed] [EuropePMC]

• Tyrosine-O-sulfated proteins of PC12 pheochromocytoma cells and their sulfation by a tyrosylprotein sulfotransferase.

  Lee R.W., Huttner W.B.

  The O-sulfation of specific proteins on tyrosine residues was studied using the rat pheochromocytoma cell line PC12 as a model system. In intact PC12 cells labeled with inorganic [35S]sulfate, the major protein substrates for sulfation on tyrosine were four acidic polypeptides with apparent molecu ... >> More

  The O-sulfation of specific proteins on tyrosine residues was studied using the rat pheochromocytoma cell line PC12 as a model system. In intact PC12 cells labeled with inorganic [35S]sulfate, the major protein substrates for sulfation on tyrosine were four acidic polypeptides with apparent molecular weights of 113,000, 105,000, 86,000, and 84,000 designated as p113, p105, p86, and p84. After labeling of intact PC12 cells with inorganic [32P]phosphate, these four proteins were also found to be phosphorylated at serine residues. Peptide mapping after limited proteolysis indicated sequence homologies between p113 and p105, and between p86 and p84. In lysed PC12 cells, p113, p105, p86, and p84 were phosphorylated at serine residues by an endogenous protein kinase using [32P] ATP. Moreover, in the cell-free preparation, an enzymatic activity was detected that was able to catalyze the sulfation of the four proteins on tyrosine residues. This sulfation reaction, which used adenosine 3'-phosphate 5'-phospho[35S]sulfate as the sulfate donor, occurred in a particulate fraction of PC12 cells and was inhibited by 5 mM EDTA. These results demonstrate the presence in PC12 cells of a novel enzyme, designated here as a tyrosylprotein sulfotransferase, and imply a role for this enzyme in the post-translational processing of specific PC12 cell proteins. << Less

  J Biol Chem 258:11326-11334(1983) [PubMed] [EuropePMC]

• Recognition of substrates by tyrosylprotein sulfotransferase. Determination of affinity by acidic amino acids near the target sites.

  Lin W.H., Larsen K., Hortin G.L., Roth J.A.

  The sulfation of proteins by tyrosylprotein sulfotransferase (TPST) is highly site-specific. In this study, we examined the sequence specificity of the target site for TPST by determining the kinetics of rat liver TPST with peptides related to the sequence of the C4 component of complement. The da ... >> More

  The sulfation of proteins by tyrosylprotein sulfotransferase (TPST) is highly site-specific. In this study, we examined the sequence specificity of the target site for TPST by determining the kinetics of rat liver TPST with peptides related to the sequence of the C4 component of complement. The data obtained from this study demonstrate that selective elimination of negative charges from the -5 to +5 region of the acceptor tyrosine, either by removal or by isosteric substitution or the acidic amino acids in the region, produced a substantial change in the Km value, with relatively little effect on Vmax. Substitutions at -1 and +1 positions increase the Km value by 22- and 4-fold, respectively, whereas removal of the acidic amino acids from the -5, -4, or +4 positions increased the Km values by a factor of 2-4. The effect of elimination of an acidic amino acid on the Km value was constant and specific for its particular position in relation to tyrosine, and the effect of modification of more than one amino acid was multiplicative. This study provides evidence that: 1) acidic residues near tyrosines promote sulfation by increasing the affinity of enzyme-substrate binding and have little effect on catalytic rate; 2) the contribution of each acidic residue to affinity for TPST is independent and varies according to position relative to the acceptor tyrosine; and 3) the enzyme interacts with a segment of at least 4-5 residues on each side of the tyrosine, with the residues on the -1 and +1 positions being the most important determinants. In general, residues on the NH2-terminal side of the tyrosine have a greater effect on affinity for TPST. << Less

  J Biol Chem 267:2876-2879(1992) [PubMed] [EuropePMC]