title: Roles of ATM and ATR-mediated DNA damage responses during lytic BK polyomavirus infection.
abstract: BK polyomavirus (BKPyV) is an emerging pathogen whose reactivation causes severe disease in transplant patients. Unfortunately, there is no specific anti-BKPyV treatment available, and host cell components that affect the infection outcome are not well characterized. In this report, we examined the relationship between BKPyV productive infection and the activation of the cellular DNA damage response (DDR) in natural host cells. Our results showed that both the ataxia-telangiectasia mutated (ATM)- and ATM and Rad-3-related (ATR)-mediated DDR were activated during BKPyV infection, accompanied by the accumulation of polyploid cells. We assessed the involvement of ATM and ATR during infection using small interfering RNA (siRNA) knockdowns. ATM knockdown did not significantly affect viral gene expression, but reduced BKPyV DNA replication and infectious progeny production. ATR knockdown had a slightly more dramatic effect on viral T antigen (TAg) and its modified forms, DNA replication, and progeny production. ATM and ATR double knockdown had an additive effect on DNA replication and resulted in a severe reduction in viral titer. While ATM mainly led to the activation of pChk2 and ATR was primarily responsible for the activation of pChk1, knockdown of all three major phosphatidylinositol 3-kinase-like kinases (ATM, ATR, and DNA-PKcs) did not abolish the activation of γH2AX during BKPyV infection. Finally, in the absence of ATM or ATR, BKPyV infection caused severe DNA damage and aberrant TAg staining patterns. These results indicate that induction of the DDR by BKPyV is critical for productive infection, and that one of the functions of the DDR is to minimize the DNA damage which is generated during BKPyV infection.
authors.affiliation: Department of Microbiology and Immunology and Comprehensive Cancer Center, University of Michigan Medical School, Ann Arbor, Michigan, United States of America.
authors.forename: Mengxi
authors.initials: M
authors.lastname: Jiang
authors.forename: Linbo
authors.initials: L
authors.lastname: Zhao
authors.forename: Monica
authors.initials: M
authors.lastname: Gamez
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Imperiale
mesh_terms: D064007:Ataxia Telangiectasia Mutated Proteins / Q000235:genetics / Q000378:metabolism*; D001739:BK Virus / Q000235:genetics / Q000502:physiology*; D002453:Cell Cycle; D002478:Cells, Cultured; D064447:Checkpoint Kinase 2 / Q000235:genetics / Q000378:metabolism; D004249:DNA Damage; D004261:DNA Replication; D055785:Gene Knockdown Techniques; D006657:Histones / Q000235:genetics / Q000378:metabolism; D006801:Humans; D008958:Models, Molecular; D027601:Polyomavirus Infections / Q000821:virology*; D011123:Polyploidy; D034741:RNA, Small Interfering; D015398:Signal Transduction; D014412:Tumor Virus Infections / Q000821:virology*; D014779:Virus Replication
chemical_list: C468783:H2AX protein, human; D006657:Histones; D034741:RNA, Small Interfering; D064447:Checkpoint Kinase 2; C576324:ATM protein, human; C576597:ATR protein, human; D064007:Ataxia Telangiectasia Mutated Proteins; C578634:CHEK2 protein, human