Selvan Nithya, Williamson Ritchie, Mariappa Daniel, Campbell David G, Gourlay Robert, Ferenbach Andrew T, Aristotelous Tonia, Hopkins-Navratilova Iva, Trost Matthias, van Aalten Daan M F
MRC Protein Phosphorylation and Ubiquitylation Unit, University of Dundee, Dundee, UK.
Division of Gene Regulation and Expression, University of Dundee, Dundee, UK.
Nat Chem Biol. 2017 Aug;13(8):882-887. doi: 10.1038/nchembio.2404. Epub 2017 Jun 12.
Protein O-GlcNAcylation is a reversible post-translational modification of serines and threonines on nucleocytoplasmic proteins. It is cycled by the enzymes O-GlcNAc transferase (OGT) and O-GlcNAc hydrolase (O-GlcNAcase or OGA). Genetic approaches in model organisms have revealed that protein O-GlcNAcylation is essential for early embryogenesis. The Drosophila melanogaster gene supersex combs (sxc), which encodes OGT, is a polycomb gene, whose null mutants display homeotic transformations and die at the pharate adult stage. However, the identities of the O-GlcNAcylated proteins involved and the underlying mechanisms linking these phenotypes to embryonic development are poorly understood. Identification of O-GlcNAcylated proteins from biological samples is hampered by the low stoichiometry of this modification and by limited enrichment tools. Using a catalytically inactive bacterial O-GlcNAcase mutant as a substrate trap, we have enriched the O-GlcNAc proteome of the developing Drosophila embryo, identifying, among others, known regulators of Hox genes as candidate conveyors of OGT function during embryonic development.
蛋白质O-连接的N-乙酰葡糖胺化是一种发生在核质蛋白丝氨酸和苏氨酸上的可逆翻译后修饰。它由O-连接的N-乙酰葡糖胺转移酶（OGT）和O-连接的N-乙酰葡糖胺水解酶（O-连接的N-乙酰葡糖胺酶或OGA）循环催化。模式生物中的遗传学方法表明，蛋白质O-连接的N-乙酰葡糖胺化对早期胚胎发育至关重要。果蝇的超性梳基因（sxc）编码OGT，它是一个多梳基因，其无效突变体表现出同源异型转化，并在成虫前期死亡。然而，目前对于所涉及的O-连接的N-乙酰葡糖胺化蛋白的身份以及将这些表型与胚胎发育联系起来的潜在机制了解甚少。从生物样品中鉴定O-连接的N-乙酰葡糖胺化蛋白受到这种修饰的低化学计量比和有限的富集工具的阻碍。我们使用一种无催化活性的细菌O-连接的N-乙酰葡糖胺酶突变体作为底物陷阱，富集了发育中的果蝇胚胎的O-连接的N-乙酰葡糖胺蛋白质组，除其他外，鉴定出已知的Hox基因调节因子作为胚胎发育过程中OGT功能的候选传递者。
