Human TPST1 transmembrane domain triggers enzyme dimerisation and localisation to the Golgi compartment.

TPST1 is a human tyrosylprotein sulfotransferase that uses 3'phosphoadenosine-5'phosphosulfate (PAPS) to transfer the sulfate moiety to proteins predominantly designated for secretion. To achieve a general understanding of the cellular role of human tyrosine-directed sulfotransferases, we investigated targeting, structure and posttranslational modification of TPST1. Golgi localisation of the enzyme in COS-7 and HeLa cells was visualised by fluorescence imaging techniques.

Structural analysis of the mitotic regulator hPin1 in solution: insights into domain architecture and substrate binding.

The peptidyl-prolyl cis/trans isomerase hPin1 is a phosphorylation-dependent regulatory enzyme whose substrates are proteins involved in regulation of cell cycle, transcription, Alzheimer's disease, and cancer pathogenesis. We have determined the solution structure of the two domain protein hPin1-(1-163) and its separately expressed PPIase domain (50-163) (hPin1PPIase) with an root mean square deviation of <0.5 A over backbone atoms using NMR.

Structural attributes in the conjugation of ubiquitin, SUMO and RUB to protein substrates.

Many cellular and secreted proteins are chemically modified after their translation is completed. The covalent linkage of a polypeptide chain (modifier) to a substrate protein is a special case of post-translational modification. In the late seventies it was observed that ubiquitin, a small modifier, marks short-lived proteins for degradation by the 26S proteasome.

Shear stress mediates tyrosylprotein sulfotransferase isoform shift in human endothelial cells.

In this study, we examined expression of tyrosylprotein sulfotransferase (TPST) isoforms TPST1 and TPST2 in primary cultures of human umbilical vein endothelial cells. For the first time coexpression of both isoforms is shown in primary human cells. Application of physiological levels of shear stress regulates expression of TPST isoforms in a time- and dose-dependent manner.