Changes in replisome composition underlie the rewiring of DNA replication during embryonic stem cell reprogramming

ABSTRACT: Pluripotent stem cells can give rise to the three embryonic germ layers and the characterization of their properties is crucial to exploit their therapeutic potential. Mouse embryonic stem cells (mESCs) are isolated and usually maintained in vitro in a primed state that resembles the post-implantation epiblast features. Furthermore, primed mESCs can be de-differentiated to a naive state that resembles the pre-implantation inner cell mass (ICM). Cell differentiation or genotoxic stress, among others, can alter DNA replication, which is a flexible process able to adapt to different cellular contexts. Here, we demonstrate that primed-to-naive mESC reprogramming triggers replication fork slowdown, increased fork asymmetry and a compensatory activation of dormant origins. Using iPOND (“isolation of proteins on nascent DNA”) coupled to mass spectrometry we have characterized the changes in replisome composition between naive and primed mESCs. Several DNA repair factors, including MRE11 nuclease, are enriched in naive mESCs forks, while factors involved in ubiquitin-dependent protein metabolism are enriched in primed mESC forks. We report that primed-to-naive mESC de-differentiation promotes recruitment of MRE11 to the forks in response to transcription-replication conflicts, underlying the DNA replication rewiring required for efficient mESC reprogramming.

INSTRUMENT(S): Q Exactive HF-X

ORGANISM(S): Mus Musculus (mouse)

TISSUE(S): Embryonic Stem Cell

SUBMITTER: Pilar Ximenez-Embun  

LAB HEAD: Javier Munoz

PROVIDER: PXD041946 | Pride | 2024-04-03

REPOSITORIES: Pride