The nuclear structural protein NuMA is a negative regulator of 53BP1 in DNA double-strand break repair
Year: 2019
Type: article
Abstract: P53-binding protein 1 (53BP1) mediates DNA repair pathway choice and promotes checkpoint activation. Chromatin marks induced by DNA double-strand breaks and recognized by 53BP1 enable focal accumulation of this multifunctional repair factor at damaged chromatin. Here, we unveil an additional level of regulation of 53BP1 outside repair foci. 53BP1 movements are constrained throughout the nucleoplasm and increase in response to DNA damage. 53BP1 interacts with the structural protein NuMA, which controls 53BP1 diffusion. This interaction, and colocalization between the two proteins in vitro and in breast tissues, is reduced after DNA damage. In cell lines and breast carcinoma NuMA prevents 53BP1 accumulation at DNA breaks, and high NuMA expression predicts better patient outcomes. Manipulating NuMA expression alters PARP inhibitor sensitivity of BRCA1-null cells, end-joining activity, and immunoglobulin class switching that rely on 53BP1. We propose a mechanism involving the sequestration of 53BP1 by NuMA in the absence of DNA damage. Such a mechanism may have evolved to disable repair functions and may be a decisive factor for tumor responses to genotoxic treatments.
Source: Nucleic Acids Research
DOI: 10.1093/nar/gkz138
Institutions: Wake Forest University Health Sciences, Wake Forest University, Indiana University – Purdue University Indianapolis, University of Minnesota, University of Chicago, University of Cincinnati, Wake Forest Baptist Comprehensive Cancer Center, Purdue University West Lafayette, Purdue University Institute for Cancer Research
Language: English
Topic: DNA Repair Mechanisms
Subfield: Molecular Biology
Domain: Life Sciences
Open Access status: gold
Estimated APC paid: $3,992
OpenAlex ID: W2918770534