Interaction of MEQ protein and C-terminal-binding protein is critical for induction of lymphomas by Marek’s disease virus

Brown, Andrew; Baigent, Susan J.; Smith, Lorraine P.; Chattoo, Jason P.; Petherbridge, Lawrence; Hawes, Philippa C.; Allday, Martin J.; Nair, Venugopal

doi:10.1073/pnas.0507595103

Cited by 105 publications

(103 citation statements)

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“…The precipitated samples were separated on a NuPAGE Novex Bistris gel, transferred to membrane using an iBlot Dry Blotting System (Invitrogen) and probed with anti-Hsp70 antibody and rabbit anti-mouse horseradish peroxidase (HRP)-labelled secondary antibody. For the detection of Meq, HRPconjugated anti-Meq mouse monoclonal antibody FD7 (Brown et al, 2006) was used. Signals were detected using ECL Western blotting detection reagents (GE Healthcare).…”

Section: Methodsmentioning

confidence: 99%

“…The N-terminal region of Meq contains a PLDLS motif, also present in other viral oncoproteins such as adenovirus E1A (Chinnadurai, 2002(Chinnadurai, , 2009) and EBV EBNA3A (Hickabottom et al, 2002), with which they interact with the transcriptional co-repressor C-terminal binding protein-1 (CtBP). Meq-CtBP interaction is crucial for MDV oncogenicity, as mutations that abolish the interaction make the virus non-oncogenic (Brown et al, 2006). In addition, Meq is also reported to interact with a number of cellular proteins such as p53 and retinoblastoma (Rb) tumour-suppressor proteins (Brunovskis et al, 1996).…”

Section: Introductionmentioning

confidence: 99%

“…Although all of the molecular mechanisms of Meq-induced oncogenicity are yet to be identified, an increasing amount of data from various laboratories suggest that the DNA-binding and transcriptional functions of Meq are strongly modulated by its interaction with multiple protein partners (Levy et al, 2005;Nair & Kung, 2004;Osterrieder et al, 2006). dimerization abolish viral oncogenicity (Brown et al, 2006), suggesting that partnering with other bZIP proteins is important for Meq oncogenicity. Recent data have also shown that homodimerization alone is insufficient for Meq-induced transformation by MDV (Suchodolski et al, 2009).…”

Section: Introductionmentioning

confidence: 99%

“…Recombinant MDV derived from the self-excisable, US 2 -restored pRB-1B*X6 virus used in these experiments was generated by transfection of the DNA into CEFs as described previously (Zhao et al, 2008). Other viruses used in the experiment included the wild-type RB-1B virus, RB-1B DMeq virus from which both copies of Meq are deleted (Brown et al, 2006) and the recombinant pRB-1B with mCherry protein (kindly received from Dr Roger Tsien, UCSD, California) fused to the N terminus of the pp38 gene (unpublished data).Generation of N-terminal Meq TAP tag pRB-1B constructs. All manipulations for the generation of recombinant viruses were carried out using a modified pRB-1B*X6 bacterial artificial chromosome (BAC) clone (Zhao et al, 2008).…”

mentioning

confidence: 99%

“…The cells were fixed in 4 % paraformaldehyde for 1 h, permeabilized by treatment with 0.1 % Triton X-100 for 15 min and blocked with 0.5 % BSA in PBS. The cells were stained with a 1 : 500 dilution of anti-chicken Hsp70 and/or a 1 : 20 dilution of anti-Meq monoclonal antibody FD7 (Brown et al, 2006) or with anti-pp38 antibody BD1 (Barrow et al, 2003) and detected with Alexa Fluor 488/568-conjugated goat anti-mouse IgG (H+L) antibody (Invitrogen). For double staining, Alexa Fluor 488-conjugated goat antimouse IgG 1 (c1) and Alexa Fluor 568-conjugated goat anti-mouse IgG 2a (c2a) were used.…”

mentioning

confidence: 99%

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Interaction of Marek's disease virus oncoprotein Meq with heat-shock protein 70 in lymphoid tumour cells

Zhao

Kurian

et al. 2009

Journal of General Virology

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Marek's disease virus (MDV) is a highly oncogenic alphaherpesvirus that induces the rapid onset of T-cell lymphomas in poultry. The MDV-encoded oncoprotein Meq plays an important role in oncogenicity, as its deletion abolishes the ability of the virus to induce tumours. It has been shown previously that Meq oncogenicity is linked to its interaction with C-terminal binding protein 1 (CtBP), a property also shared by other virus-encoded oncoproteins such as adenovirus E1A and Epstein-Barr virus EBNA3A and -3C. Therefore, this study examined whether Meq also shares the properties of these viral oncoproteins in interacting with other binding partners such as heatshock protein 70 (Hsp70), a molecular chaperone protein linked to multiple cellular functions including neoplastic transformation. Confocal microscopic analysis demonstrated that MDV infection induced nuclear accumulation of Hsp70 and its co-localization with Meq. Biochemical evidence of Meq-Hsp70 interaction was obtained by two-way immunoprecipitation with Meqand Hsp70-specific antibodies. To demonstrate further the Meq-Hsp70 interaction in virusinduced lymphomas, recombinant MDV was generated expressing an N-terminal tandem affinity purification (TAP) tag-fused Meq by mutagenesis of the infectious BAC clone of the oncogenic MDV strain RB-1B. Demonstration of Hsp70 in the TAP-tag affinity purified Meq from tumours induced by the recombinant virus, using quadrupole time-of-flight tandem mass spectrometry analysis, further confirmed the Meq-Hsp70 interaction in the transformed lymphocytes. Given the well-documented evidence of the tumorigenic properties of Hsp70 and its interaction with a number of other known viral oncoproteins, demonstration of the interaction of Meq and Hsp70 is significant in MDV oncogenesis. INTRODUCTIONCurrent estimates suggest that viruses are involved in 15-20 % of human cancers worldwide (Javier & Butel, 2008). Oncogenic viruses, as efficient inducers of cancers, have helped significantly in understanding the molecular mechanisms of oncogenesis. Marek's disease (MD), a highly oncogenic viral disease induced by Marek's disease virus (MDV), is widely seen as a natural model for virusinduced lymphomas (Calnek, 1986;Osterrieder et al., 2006). MDV induces rapid-onset CD4 + T-cell lymphomas within a few weeks of infection, and MD lymphomas have many biological parallels with tumours associated with human herpesviruses such as Epstein-Barr virus (EBV) and Kaposi's sarcoma herpesvirus (KSHV, human herpesvirus 8). For example, it has recently been shown that MDV and KSHV both encode an oncogenic microRNA-155 orthologue (Gottwein et al., 2007;Zhao et al., 2009), whilst EBV strongly induces host microRNA-155 expression (Yin et al., 2008). However, the most important viral gene associated with MD oncogenicity is Meq (MDV EcoRI Q), encoded from the repeat region (IR L /TR L ) of the MDV genome (Jones et al., 1992;Nair & Kung, 2004). The direct role of Meq in MDV oncogenicity has been clearly demonstrated by the abolition of oncogenicity in Meq-de...

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Section: Methodsmentioning

confidence: 99%