Shear stress mediates tyrosylprotein sulfotransferase isoform shift in human endothelial cells

Human TPST1 Transmembrane Domain Triggers Enzyme Dimerisation and Localisation to the Golgi Compartment

“…In CD spectra, a strong negative ellipticity at 208 and 222 nm is generally used as indication for α-helix formation, whereas a strong negative band at 215 nm and zeropassage at 210 nm are considered to represent β-strand formation. By varying the content of TFE in [8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25] , which lacks all flanking residues, is diffusely distributed, suggesting that the TMD alone is not able to sustain the Golgi localisation. The bar represents 10 μm.…”

“…solution, a corresponding variation in secondary structure of TPST1 TMD (9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19)(20)(21)(22)(23)(24)(25) could be monitored as shown in Figure 9(a). As the TFE concentration increased, the negative ellipticity increased proportionally, suggesting an induced gain in secondary structure.…”

“…TPST1 and 2 are expressed in various human tissues 13,14,18 and are co-expressed in primary umbilical vein endothelial cells (HUVECs) in a shear stress-dependent manner. 19 Despite the fact that mammalian TPST variants have already been studied for several years, their function is barely understood and many questions concerning their biochemical and structural characterisation remain open. Although it is generally accepted that TPSTs are localised in the trans-Golgi apparatus, the determinant responsible for Golgi targeting has not been described so far.…”

Heterodimers of Tyrosylprotein Sulfotransferases Suggest Existence of a Higher Organization Level of Transferases in the Membrane of the trans-Golgi Apparatus

“…Additionally, the changing expression profiles of TPST isoforms in umbilical vein cells observed upon shear stress indicate the presence of different substrate molecules for TPST1 and TPST2 [26]. With the consideration of all of this, the process of tyrosine sulfation coding and substrate selection of TPSTs remains elusive in vivo.…”

SULFATION PATHWAYS: Insights into steroid sulfation and desulfation pathways

“…Protein substrates have to locally unfold and bind in a deep active site cleft to TPSTs and the vicinity of the acceptor tyrosine residues adopts an intrinsically unfolded conformation in order to facilitate this process (Teramoto et al 2013, Tanaka et al 2017. TPSTs were known to fulfill different biological functions; shear stress applied to primary cultures of human umbilical vein endothelial cells lead to downregulation of TPST1 via protein kinase C, but to upregulation of TPST2 via a tyrosine kinase-dependent pathway (Goettsch et al 2002(Goettsch et al , 2006. However, there are no obvious differences in the substrate-binding site of TPST1 and 2; these need to be hidden in other nonconserved residues in the periphery.…”