Title : Human
TPST1 transmembrane
domain triggers enzyme
dimerisation and localisation to the Golgi compartment
Abstract :
- 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
- PNGase treatment and mutational studies determined that TPST1 bears N-linked glycosyl residues exclusively at position Asn60 and Asn262
- By alanine mutation of these asparagine residues , we could determine that the N-linked oligosaccharides do not have an influence on Golgi retention of TPST1
- In concert with N and C-terminal flanking residues , the transmembrane domain of TPST1 was determined to act in targeting and retention of the enzyme to the trans-Golgi compartment
- This domain exhibits a pronounced secondary structure in a lipid environment
- Further in vivo FRET studies using the transmembrane domain suggest that the human tyrosylprotein sulfotransferase may be functional as homodimer/oligomer in the trans-Golgi compartment
Output (sent_index, trigger,
protein,
sugar,
site):
- 4. bears, , TPST1, N-linked glycosyl residues, position Asn60 and Asn262
Output(Part-Of) (sent_index,
protein,
site):
- 0. TPST1, domain
- 6. TPST1, domain
*Output_Site_Fusion* (sent_index,
protein,
sugar,
site):
- 4. TPST1, N-linked glycosyl residues, position Asn60 and Asn262