AUTHOR=Wang Jiajia , Dou Biao , Zheng Lu , Cao Wei , Dong Peiyu , Chen Yingyi , Zeng Xueke , Wen Yinhang , Pan Wenxuan , Ma Jing , Chen Jingying , Li Xia 

TITLE=The Metabolic Chemical Reporter Ac46AzGal Could Incorporate Intracellular Protein Modification in the Form of UDP-6AzGlc Mediated by OGT and Enzymes in the Leloir Pathway

JOURNAL=Frontiers in Chemistry

VOLUME=Volume 9 - 2021

YEAR=2021

URL=https://www.frontiersin.org/journals/chemistry/articles/10.3389/fchem.2021.708306

DOI=10.3389/fchem.2021.708306

ISSN=2296-2646

ABSTRACT=Galactose is a naturally occurring monosaccharide used to build complex glycans that has not been targeted for labeling as a metabolic reporter. We here characterize the cellular modification of proteins by using Ac46AzGal in a manner of concentration- and time-dependent. It is note that vast majority of this labeling of Ac46AzGal occurs intracellularly in a range of mammalian cells. We also provide evidence that labeling is not only dependent on the enzymes of OGT and OGA responsible for O-GlcNAcylation, but also the enzymes of GALT and GALE in Leloir pathway. Notably, these discoveries support the conclusion of substrate promiscuity of OGT, highlighting the possibility that intracellular O-galactose modification may be a widespread event under certain conditions, such as galactosemias, characterized with impaired function of the Leloir pathway of galactose metabolism.