Glycosyltransferases: Structure and Function II


On 21th June morning, the session of "Glycosyltransferases: Structure and Function II" was successfully conducted at the Triumphant Hall of the Seaview Garden Hotel. Prof. Michael Pierce and Prof. Xiaolian Zhang chaired this session. Prof. Yan Zhang, Prof. Xiaodong Gao, Prof. Yasuhiko Kizuka, Prof. Lianwen Zhang and Prof. Jing Li made wonderful presentations. The overview of this session is as follows:

As the first speaker of this session, Prof. Yan Zhang (Shanghai Jiao Tong University, China) paid attention to the polypeptide N-acetylgalactosaminyltransferase (ppGalNAc-T). In their studies, an on-chip ppGalNAc-T assay was constructed to systematically study the protein substrate specificity of each ppGalNAc-T isoform. Besides, they proved that fine-tuning the function of protein by O-GalNAc glycosylation was a precise controlling process due to the different activities and substrate preferences of ppGalNAc-T isoforms.

Prof. Xiaodong Gao

Prof. Xiaodong Gao (Jiangnan University, China) made a presentation about his enzymatic studies on cytoplasmic mannosyltransferase (Alg1, Alg2 and Alg11) of dolichol-linked oligosaccharide (DLO) pathway. A series of ER-resident glycosyltransferases are responsible for the biosynthesis of DLO sugars. Based on this principle, they have successfully established an LC-MS-based in vitro quantitative assay to analyze activities of Algs.

Prof. Yasuhiko Kizuka

In Prof. Yasuhiko Kizuka’s (Gifu University, Japan) presentation, N-glycan structures of GnT-III knockout brains were analyzed by MS. He and his co-workers found that various types of terminal modifications of N-glycan were increased by knocking out bisecting GlcNAc. Therefore, bisecting GlcNAc negatively can regulate various terminal modifications of N-glycans.

Prof. Lianwen Zhang

Prof. Lianwen Zhang (Nankai University, China) introduced the role of O-GlcNAcylation on short form OGT (sOGT). His group found that O-GlcNAcylation of sOGT does not affect the enzyme activity but increases its binding to substrate proteins. Their findings demonstrate that the O-GlcNAc pattern on sOGT modulates its function in cells by targeting different proteins.

Prof. Jing Li

The last speaker, Prof. Jing Li (Capital Normal University, China), made a presentation about OGT. Her group identified OGT as one of Chk1’s substrates, and found that Chk1 interacts with and phosphorylates OGT at Ser-20, which not only stabilizes OGT, but also is required for cytokinesis. Their results suggest a Chk1–OGT–vimentin pathway that regulates the intermediate filament network during cytokinesis.