RT Journal Article
SR Electronic
T1 A natural variation-based screen in mouse cells reveals USF2 as a regulator of the DNA damage response and cellular senescence
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 2022.04.21.489100
DO 10.1101/2022.04.21.489100
A1 Taekyu Kang
A1 Emily C. Moore
A1 Emily E. K. Kopania
A1 Christina D. King
A1 Birgit Schilling
A1 Judith Campisi
A1 Jeffrey M. Good
A1 Rachel B. Brem
YR 2023
UL http://biorxiv.org/content/early/2023/01/23/2022.04.21.489100.abstract
AB Cellular senescence is a program of cell cycle arrest, apoptosis resistance, and cytokine release induced by stress exposure in metazoan cells. Landmark studies in laboratory mice have characterized a number of master senescence regulators, including p16INK4a, p21, NF-kB, p53, and C/EBPβ. To discover other molecular players in senescence, we developed a screening approach to harness the evolutionary divergence between mouse species. We found that primary cells from the Mediterranean mouse Mus spretus, when treated with DNA damage to induce senescence, produced less cytokine and had less-active lysosomes than cells from laboratory M. musculus. We used allele-specific expression profiling to catalog senescence-dependent cis-regulatory variation between the species at thousands of genes. We then tested for correlation between these expression changes and interspecies sequence variants in the binding sites of transcription factors. Among the emergent candidate senescence regulators, we chose a little-studied cell cycle factor, USF2, for molecular validation. In acute irradiation experiments, cells lacking USF2 had compromised DNA damage repair and response. Longer-term senescent cultures without USF2 mounted an exaggerated senescence regulatory program—shutting down cell cycle and DNA repair pathways, and turning up cytokine expression, more avidly than wild-type. We interpret these findings under a model of pro-repair, anti-senescence regulatory function by USF2. Our study affords new insights into the mechanisms by which cells commit to senescence, and serves as a validated proof of concept for natural variation-based regulator screens.Competing Interest StatementThe authors have declared no competing interest.