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Kutle I, Szymańska-de Wijs KM, Bogdanow B, Cuvalo B, Steinbrück L, Jonjić S, Wagner K, Niedenthal R, Selbach M, Wiebusch L, Dezeljin M, Messerle M. Murine Cytomegalovirus M25 Proteins Sequester the Tumor Suppressor Protein p53 in Nuclear Accumulations. J Virol 2020; 94:e00574-20. [PMID: 32727874 PMCID: PMC7527045 DOI: 10.1128/jvi.00574-20] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2020] [Accepted: 07/22/2020] [Indexed: 02/06/2023] Open
Abstract
To ensure productive infection, herpesviruses utilize tegument proteins and nonstructural regulatory proteins to counteract cellular defense mechanisms and to reprogram cellular pathways. The M25 proteins of mouse cytomegalovirus (MCMV) belong to the betaherpesvirus UL25 gene family that encodes viral proteins implicated with regulatory functions. Through affinity purification and mass spectrometric analysis, we discovered the tumor suppressor protein p53 as a host factor interacting with the M25 proteins. M25-p53 interaction in infected and transfected cells was confirmed by coimmunoprecipitation. Moreover, the proteins colocalized in nuclear dot-like structures upon both infection and inducible expression of the two M25 isoforms. p53 accumulated in wild-type MCMV-infected cells, while this did not occur upon infection with a mutant lacking the M25 gene. Both M25 proteins were able to mediate the effect, identifying them as the first CMV proteins responsible for p53 accumulation during infection. Interaction with M25 proteins led to substantial prolongation of the half-life of p53. In contrast to the higher abundance of the p53 protein in wild-type MCMV-infected cells, the transcript levels of the prominent p53 target genes Cdkn1a and Mdm2 were diminished compared to cells infected with the ΔM25 mutant, and this was associated with reduced binding of p53 to responsive elements within the respective promoters. Notably, the productivity of the M25 deletion mutant was partially rescued on p53-negative fibroblasts. We propose that the MCMV M25 proteins sequester p53 molecules in the nucleus of infected cells, reducing their availability for activating a subset of p53-regulated genes, thereby dampening the antiviral role of p53.IMPORTANCE Host cells use a number of factors to defend against viral infection. Viruses are, however, in an arms race with their host cells to overcome these defense mechanisms. The tumor suppressor protein p53 is an important sensor of cell stress induced by oncogenic insults or viral infections, which upon activation induces various pathways to ensure the integrity of cells. Viruses have to counteract many functions of p53, but complex DNA viruses such as cytomegaloviruses may also utilize some p53 functions for their own benefit. In this study, we discovered that the M25 proteins of mouse cytomegalovirus interact with p53 and mediate its accumulation during infection. Interaction with the M25 proteins sequesters p53 molecules in nuclear dot-like structures, limiting their availability for activation of a subset of p53-regulated target genes. Understanding the interaction between viral proteins and p53 may allow to develop new therapeutic strategies against cytomegalovirus and other viruses.
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Affiliation(s)
- Ivana Kutle
- Institute of Virology, Hannover Medical School, Hannover, Germany
| | | | - Boris Bogdanow
- Proteome Dynamics lab, Max Delbrück Center for Molecular Medicine, Berlin, Germany
- Department of Chemical Biology, Leibniz-Forschungsinstitut für Molekulare Pharmakologie, Berlin, Germany
| | - Berislav Cuvalo
- Institute of Virology, Hannover Medical School, Hannover, Germany
| | - Lars Steinbrück
- Institute of Virology, Hannover Medical School, Hannover, Germany
| | - Stipan Jonjić
- Department of Histology and Embryology, Faculty of Medicine, University of Rijeka, Rijeka, Croatia
| | - Karen Wagner
- Institute of Virology, Hannover Medical School, Hannover, Germany
| | - Rainer Niedenthal
- Institute of Cell Biochemistry, Hannover Medical School, Hannover, Germany
| | - Matthias Selbach
- Proteome Dynamics lab, Max Delbrück Center for Molecular Medicine, Berlin, Germany
| | - Lüder Wiebusch
- Laboratory of Pediatric Molecular Biology, Charité Universitätsmedizin Berlin, Berlin, Germany
| | - Martina Dezeljin
- Institute of Virology, Hannover Medical School, Hannover, Germany
| | - Martin Messerle
- Institute of Virology, Hannover Medical School, Hannover, Germany
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Smith RM, Kosuri S, Kerry JA. Role of human cytomegalovirus tegument proteins in virion assembly. Viruses 2014; 6:582-605. [PMID: 24509811 PMCID: PMC3939473 DOI: 10.3390/v6020582] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2014] [Revised: 02/04/2014] [Accepted: 02/04/2014] [Indexed: 11/26/2022] Open
Abstract
Like other herpesviruses, human cytomegalovirus (HCMV) contains a unique proteinaceous layer between the virion envelope and capsid, termed the tegument. Upon infection, the contents of the tegument layer are delivered to the host cell, along with the capsid and the viral genome, where they facilitate the initial stages of virus replication. The tegument proteins also play important roles in virion assembly and this dual nature makes them attractive potential targets for antiviral therapies. While our knowledge regarding tegument protein function during the initiation of infection has been the subject of intense study, their roles in assembly are much less well understood. In this review, we will focus on recent studies that highlight the functions of HCMV tegument proteins during assembly, and pose key questions for further investigation.
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Affiliation(s)
- Rebecca Marie Smith
- Department of Microbiology and Molecular Cell Biology, Eastern Virginia Medical School, Norfolk, VA 23501, USA.
| | - Srivenkat Kosuri
- Department of Microbiology and Molecular Cell Biology, Eastern Virginia Medical School, Norfolk, VA 23501, USA.
| | - Julie Anne Kerry
- Department of Microbiology and Molecular Cell Biology, Eastern Virginia Medical School, Norfolk, VA 23501, USA.
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