Genetic encoding of a stable O-GlcNAc analogue

Abstract

Attachment of N-acetylglucosamine to hydroxyl groups of serine and threonine residues of intracellular proteins is known as O-GlcNAcylation, an essential posttranslational event in mammals and most other metazoa, catalysed by a unique O-GlcNAc transferase (OGT) and removed by an O-GlcNAc hydrolase (OGA). Despite the existence of a single writer/eraser pair, proteomic studies have identified over 4000 O-GlcNAcylated proteins in the nucleus, cytoplasm and mitochondria of various organisms, ranging from C. elegans to human. However, the molecular and biological mechanistic consequences of site-specific O-GlcNAcylation have been understudied due to the lack of appropriate tools. The function of O-GlcNAc modification in the context of specific sites in vivo is usually examined by a loss-offunction Ser/Thr to Ala mutation. The only available tool to study gain-of-function O-GlcNAcylation in vivo is OGA inhibition, which causes global elevation of O-GlcNAcylation levels, complicating the dissection of site-specific modification. This thesis describes the development of approaches to study O-GlcNAcylation in a protein and site-specific manner. Due to the labile nature of O-GlcNAc and susceptibility to OGA hydrolysis, methods for site-targeted incorporation of its non-hydrolysable analogue were explored.

Date of Award	2018
Original language	English
Awarding Institution	University of Dundee
Sponsors	Wellcome Trust
Supervisor	Daan van Aalten (Supervisor)