Functional compartmentalization of Rad9 and Hus1 reveals diverse assembly of the 9-1-1 complex components during the DNA damage response in Leishmania

Damasceno, J. D., Obonaga, R., Santos, E. V., Scott, A., McCulloch, R. and Tosi, L. R.O. (2016) Functional compartmentalization of Rad9 and Hus1 reveals diverse assembly of the 9-1-1 complex components during the DNA damage response in Leishmania. Molecular Microbiology, 101(6), pp. 1054-1068. (doi:10.1111/mmi.13441) (PMID:27301589) (PMCID:PMC5453112)

[img]
Preview
Text
121059.pdf - Published Version
Available under License Creative Commons Attribution.

795kB

Abstract

The Rad9-Rad1-Hus1 (9-1-1) complex is a key component in the coordination of DNA damage sensing, cell cycle progression and DNA repair pathways in eukaryotic cells. This PCNA-related trimer is loaded onto RPA-coated single stranded DNA and interacts with ATR kinase to mediate effective checkpoint signaling to halt the cell cycle and to promote DNA repair. Beyond these core activities, mounting evidence suggests that a broader range of functions can be provided by 9-1-1 structural diversification. The protozoan parasite Leishmania is an early-branching eukaryote with a remarkably plastic genome, which hints at peculiar genome maintenance mechanisms. Here, we investigated the existence of homologs of the 9-1-1 complex subunits in L. major and found that LmRad9 and LmRad1 associate with chromatin in response to replication stress and form a complex in vivo with LmHus1. Similar to LmHus1, LmRad9 participates in telomere homeostasis and in the response to both replication stress and double strand breaks. However, LmRad9 and LmHus1-deficient cells present markedly opposite phenotypes, which suggest their functional compartmentalization. We show that some of the cellular pool of LmRad9 forms an alternative complex and that some of LmHus1 exists as a monomer. We propose that the diverse assembly of the Leishmania 9-1-1 subunits mediates functional compartmentalization, which has a direct impact on the response to genotoxic stress.

Item Type:Articles
Status:Published
Refereed:Yes
Glasgow Author(s) Enlighten ID:McCulloch, Professor Richard and Damasceno, Dr Jeziel and Scott, Mr Alan
Authors: Damasceno, J. D., Obonaga, R., Santos, E. V., Scott, A., McCulloch, R., and Tosi, L. R.O.
College/School:College of Medical Veterinary and Life Sciences > Institute of Infection Immunity and Inflammation
Journal Name:Molecular Microbiology
Publisher:Wiley
ISSN:0950-382X
ISSN (Online):1365-2958
Published Online:19 July 2016
Copyright Holders:Copyright © 2016 The Authors
First Published:First published in Molecular Microbiology 101(6):1054-1068
Publisher Policy:Reproduced under a Creative Commons License

University Staff: Request a correction | Enlighten Editors: Update this record

Project CodeAward NoProject NamePrincipal InvestigatorFunder's NameFunder RefLead Dept
371796The Wellcome Centre for Molecular Parasitology ( Core Support )Andrew WatersWellcome Trust (WELLCOME)085349/Z/08/ZIII - PARASITOLOGY
463981Characterisation of Orc1/Cdc6 and DNA replication initiation in Trypanosoma brucei.Richard McCullochWellcome Trust (WELLCOME)083485/Z/07/ZIII - PARASITOLOGY
606431Kinase dependent control of DNA replication and repair as a drug target in Trypanosoma brucei.Richard McCullochBiotechnology and Biological Sciences Research Council (BBSRC)BB/K006495/1III - PARASITOLOGY