Peptide posttranslational modifications have been shown to regulate multiple aspects of cell signalling, thereby influencing cellular functions. The addition of O-linked Nacetylglucosamine to serine or threonine residues (O-GlcNAcylation) of proteins has only recently been characterized and its overall role in cell signalling remains elusive to date. Recent studies suggest an essential role of O-GlcNAcylation on the viability and pluripotency of mouse and human embryonic stem (ES) cells. Here we show that increased levels of O-GlcNAcylation in response to specific inhibition of O-GlcNAc hydrolase (Oga) hinder mouse ES cell differentiation. In addition to these findings, I could also demonstrate that increased O-GlcNAcylation leads to expression of a gene set normally epigenetically repressed in mouse ES cells and associated with a subpopulation resembling cells in the 2-cell-stage embryo. I also extended our lab's investigations to human induced pluripotent stem (iPS) cells. While mesendodermal differentiation remains unaffected by high O-GlcNAc levels, neural differentiation is severely disrupted in these cells. Human iPS cells with elevated O-GlcNAcylation are unable to commit to the ectodermal lineage and fail to organize in neural tube-like structures, so-called neural rosettes. Following these observations we performed mRNA sequencing analysis on human iPS cells with high O-GlcNAc levels and found gene expression to be significantly altered. Genes affected by increased O-GlcNAcylation include modulators of key neural developmental processes, for example components of the bone morphogenic protein signalling cascade.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:699484 |
| Date | January 2016 |
| Creators | Domke, Tanja Carolina Elisabeth |
| Contributors | Stavridis, Marios |
| Publisher | University of Dundee |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | https://discovery.dundee.ac.uk/en/studentTheses/e84ff9a1-a4ab-41d0-828c-60a191b42c69 |
Page generated in 0.0022 seconds