Speaker
Description
The UGT2B7 glucuronidation activity affected by its homo- or dimerization
Authors:
J. Xue (1), H.T. Zhang (2), S. Zeng (2)
Affiliations:
(1)West China Hospital, Sichuan University, Chengdu, 610041, P. R. China
(2) College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, 310058, P. R. China
Abstract:
Background: UGT2B7 is one of the most important UGTs that glucuronidates abundant endobiotics and xenobiotics, and has been observed to form homo- or heterodimers that affect its enzymatic activities.
Methods: we investigated UGT2B7 protein-protein interactions(PPI) and the influence of three mutations (H35A, H268Y, and N68A/N315A) and four truncations (signal peptide, single transmembrane helix, cytosolic tail, and di-lysine motif) in UGT2B7 on its heterodimerization with wild-type UGT1A9 by performing a systematic quantitative fluorescence resonance energy transfer (FRET) analysis in combination with co-immunoprecipitation (Co-IP) assay.
Results: The different UGT1A9 and UGT2B7 allozyme dimers showed distinct differences in FRET efficiencies and donor-acceptor distances, indicating differences in interaction ability. In addition, the glucuronidation activities of heterodimers were further tested with zidovudine as the substrate of UGT2B7 and with propofol as the substrate of UGT1A9. The study revealed that the H35A mutation in UGT2B7 affected the affinity of PPI, leading to discernable variations in FRET efficiencies and catalytic activity.
Conclusions: These results provide insights into in-depth understanding of UGT1A9-UGT2B7 heterodimer and the association between dimerization and glucuronidation activity.
Acknowledgments:
This work was supported by the National Natural Science Foundation of China (Grant No. 82473995)
