Biology subjects

Lecona, E.

Publications and source records attributed to Lecona, E..

3 recordsLinked to original sources

bioRxiv2026

EpiFlow: multidimensional single-cell epigenetic profiling by spectral flow cytometry

The epigenetic landscape of individual cells determines their identity and function, yet current methods for profiling chromatin modifications at single-cell resolution remain low-throughput, costly, or limited in parametric depth. Here we present EpiFlow, a spectral flow cytometry-based platform that enables the simultaneous quantification of 16 epigenetic markers, including histone post-translational modifications, DNA methylation, and hydroxymethylation, at the single-cell level. We demonstrate that EpiFlow is robust across species from yeast to mammals and resolves biologically meaningful epigenetic transitions during the cell cycle, stem cell differentiation, germinal centre B cell maturation, diabetic liver remodelling, and seizure-induced chromatin reprogramming. High-dimensional integration of EpiFlow data enables cell-type classification based solely on epigenetic profiles in liver, brain, blood, and cancer. Furthermore, EpiFlow detects on-target and off-target/indirect effects of epigenetic drugs in a high-throughput-compatible format. Collectively, these results establish EpiFlow as a broadly applicable platform for single-cell epigenetic analysis in basic, pharmaceutical, and translational research.

cell biology↗

bioRxiv2022

VCP/p97 extracts DNA polymerase alfa/Primase from chromatin to limit the activation of the replication stress response

The replication stress response is an essential pathway that deals with the obstacles that halt the progression of DNA replication forks even during an unperturbed S phase. Basal activation of the ATR and CHK1 kinases prevents the premature firing of origins of replication during S phase, avoiding the activation of an excessive number of replication forks and the appearance of genomic instability. However, the mechanisms that regulate ATR activation in the unperturbed S phase have not been fully determined. Here we present evidence that the AAA ATPase VCP/p97 regulates the presence of the DNA polymerase /Primase complex (POLA/PRIM) on chromatin, thus limiting its activity and hampering the subsequent activation of ATR by TOPBP1. As a consequence, inhibiting VCP/p97 activates ATR and CHK1 and leads to a cell cycle arrest in G2/M. We propose that the priming activity of POLA/PRIM in the lagging strand is one of the determinants of the basal activation of ATR during an unperturbed S phase and VCP/p97 limits this activation through the extraction of POLA/PRIM from chromatin.

molecular biology↗

bioRxiv2018

USP7 couples DNA replication termination to mitotic entry.

To ensure a faithful segregation of chromosomes, DNA must be fully replicated before mitotic entry. However, how cells sense the completion of DNA replication and to what extent this is linked to the activation of the mitotic machinery remains poorly understood. We previously showed that USP7 is a replisome-associated deubiquitinase with an essential role in DNA replication. Here, we reveal that USP7 inhibition leads to the ubiquitination of MCM7, a hallmark of DNA replication termination. In addition, USP7 inhibition leads to the ubiquitination of additional replisome components such as POLD1, which are displaced from replisomes. Surprisingly, this premature termination of DNA replication occurs concomitant to a generalized activation of CDK1 throughout the entire cell cycle, which impairs chromosome segregation and is toxic for mammalian cells. Accordingly, the toxicity of USP7 inhibitors is alleviated by CDK1 inhibition. Our work sheds light into the mechanism of action of USP7 inhibitors and provides evidence to the concept that DNA replication termination is coupled to the activation of the mitotic program.

cell biology↗