UCL Discovery
UCL home » Library Services » Electronic resources » UCL Discovery

Requirement of Heterogeneous Nuclear Ribonucleoprotein C for BRCA Gene Expression and Homologous Recombination

Anantha, RW; Alcivar, AL; Ma, J; Cai, H; Simhadri, S; Ule, J; Konig, J; (2013) Requirement of Heterogeneous Nuclear Ribonucleoprotein C for BRCA Gene Expression and Homologous Recombination. PLoS One , 8 (4) , Article e61368. 10.1371/journal.pone.0061368. Green open access

[img]
Preview
PDF
1392060.pdf

Download (5MB)

Abstract

BACKGROUND: Heterogeneous nuclear ribonucleoprotein C1/C2 (hnRNP C) is a core component of 40S ribonucleoprotein particles that bind pre-mRNAs and influence their processing, stability and export. Breast cancer tumor suppressors BRCA1, BRCA2 and PALB2 form a complex and play key roles in homologous recombination (HR), DNA double strand break (DSB) repair and cell cycle regulation following DNA damage. METHODS: PALB2 nucleoprotein complexes were isolated using tandem affinity purification from nuclease-solubilized nuclear fraction. Immunofluorescence was used for localization studies of proteins. siRNA-mediated gene silencing and flow cytometry were used for studying DNA repair efficiency and cell cycle distribution/checkpoints. The effect of hnRNP C on mRNA abundance was assayed using quantitative reverse transcriptase PCR. RESULTS AND SIGNIFICANCE: We identified hnRNP C as a component of a nucleoprotein complex containing breast cancer suppressor proteins PALB2, BRCA2 and BRCA1. Notably, other components of the 40S ribonucleoprotein particle were not present in the complex. hnRNP C was found to undergo significant changes of sub-nuclear localization after ionizing radiation (IR) and to partially localize to DNA damage sites. Depletion of hnRNP C substantially altered the normal balance of repair mechanisms following DSB induction, reducing HR usage in particular, and impaired S phase progression after IR. Moreover, loss of hnRNP C strongly reduced the abundance of key HR proteins BRCA1, BRCA2, RAD51 and BRIP1, which can be attributed, at least in part, to the downregulation of their mRNAs due to aberrant splicing. Our results establish hnRNP C as a key regulator of BRCA gene expression and HR-based DNA repair. They also suggest the existence of an RNA regulatory program at sites of DNA damage, which involves a unique function of hnRNP C that is independent of the 40S ribonucleoprotein particles and most other hnRNP proteins.

Type: Article
Title: Requirement of Heterogeneous Nuclear Ribonucleoprotein C for BRCA Gene Expression and Homologous Recombination
Open access status: An open access version is available from UCL Discovery
DOI: 10.1371/journal.pone.0061368
Publisher version: http://dx.doi.org/10.1371/journal.pone.0061368
Language: English
Additional information: © 2013 Anantha et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
UCL classification: UCL
UCL > Provost and Vice Provost Offices
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 Brain Sciences
UCL > Provost and Vice Provost Offices > School of Life and Medical Sciences > Faculty of Brain Sciences > UCL Queen Square Institute of Neurology
UCL > Provost and Vice Provost Offices > School of Life and Medical Sciences > Faculty of Brain Sciences > UCL Queen Square Institute of Neurology > Department of Neuromuscular Diseases
URI: https://discovery.ucl.ac.uk/id/eprint/1392060
Downloads since deposit
136Downloads
Download activity - last month
Download activity - last 12 months
Downloads by country - last 12 months

Archive Staff Only

View Item View Item