Azzarelli, Roberta;
Gillen, Sarah;
Connor, Frances;
Lundie-Brown, Jethro;
Puletti, Francesca;
Drummond, Rosalind;
Raffaelli, Ana;
(2024)
Phospho-regulation of ASCL1-mediated chromatin opening during cellular reprogramming.
Development
, 151
(24)
, Article dev204329. 10.1242/dev.204329.
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Abstract
The proneural transcription factor ASCL1 regulates neurogenesis and drives somatic cell reprogramming into neurons. However, not all cell types can be reprogrammed by ASCL1, raising the questions of what provides competence and how we can overcome barriers to enable directed differentiation. Here, we investigate how levels of ASCL1 and its phosphorylation modulate its activity over progressive lineage restriction of mouse embryonic stem cells. We find that inhibition of ASCL1 phosphorylation enhances reprogramming of both mesodermal and neuroectodermal cells, while pluripotent cells remain refractory to ASCL1-directed neuronal differentiation. By performing RNA-seq and ATAC-seq in neuroectoderm, we find that un(der)phosphorylated ASCL1 causes increased chromatin accessibility at sites proximal to neuronal genes, accompanied by their increased expression. Combined analysis of protein stability and proneural function of phosphomutant and phosphomimetic ASCL1 reveals that protein stability plays only a marginal role in regulating activity, while changes in amino acid charge cannot fully explain enhanced activity of the serine-proline mutant variants of ASCL1. Our work provides new insights into proneural factor activity and regulation, and suggests ways to optimize reprogramming protocols in cancer and regenerative medicine.
| Type: | Article |
|---|---|
| Title: | Phospho-regulation of ASCL1-mediated chromatin opening during cellular reprogramming |
| Open access status: | An open access version is available from UCL Discovery |
| DOI: | 10.1242/dev.204329 |
| Publisher version: | https://doi.org/10.1242/dev.204329 |
| Language: | English |
| Additional information: | Copyright © 2024. Published by The Company of Biologists Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (https://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution and reproduction in any medium provided that the original work is properly attributed. |
| Keywords: | Neurogenesis, Cell fate reprogramming, Proneural transcription factors, Embryonic stem cells, Chromatin accessibility, Phosphorylation |
| UCL classification: | UCL UCL > Provost and Vice Provost Offices > School of Life and Medical Sciences UCL > Provost and Vice Provost Offices > School of Life and Medical Sciences > Faculty of Life Sciences UCL > Provost and Vice Provost Offices > School of Life and Medical Sciences > Faculty of Life Sciences > UCL School of Pharmacy |
| URI: | https://discovery.ucl.ac.uk/id/eprint/10200331 |
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