Cooperative Actions of HIV-1 Vpr and p53 Modulate Viral Gene Transcription

Sawaya, Bassel E.; Khalili, Kamel; Mercer, W E; Denisova, L. I.; Amini, Shohreh

doi:10.1074/jbc.273.32.20052

Cited by 90 publications

(74 citation statements)

References 41 publications

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“…Vpr can induce several promoters, including the HIV-1 LTR and p21 WAF1 (Wang et al, 1995;Amini et al, 2004). These studies suggest that cooperativity between several cellular proteins including Sp1 (Wang et al, 1995), p300 (Kino et al, 2002) and p53 (Sawaya et al, 1998) is necessary for Vpr-induced regulation of the HIV-LTR. Vpr was also shown to cause cell differentiation and DNA damage (Shimura et al, 1999a, b).…”

Section: Introductionmentioning

confidence: 78%

“…Several Vpr mutants containing either point mutations or deletion of several amino acids were used (Wang et al, 1995;Sawaya et al, 1998Sawaya et al, , 1999Zhou and Ratner, 2000). Vpr mutant expression plasmids were transfected Frag.…”

Section: Resultsmentioning

confidence: 99%

“…The pcDNA 3 -Vpr full length and its deletion mutants, EGFPSpectrin, EGFP-Vpr and HIV-LTR-CAT constructs were described previously (Sawaya et al, 1998(Sawaya et al, , 1999(Sawaya et al, , 2000. The human astrocytic cell line, U-87MG, was maintained in Dulbecco's modified Eagle's medium (DMEM) containing 10% fetal calf serum (FCS) and supplemented with antibiotics.…”

Section: Plasmids Cell Culture and Transfection Assaysmentioning

confidence: 99%

“…Each transfection was repeated multiple times with different plasmid preparations. Cell extracts were prepared 48 h after transfection, and CAT assays were performed as described previously (Sawaya et al, 1998).…”

Section: Plasmids Cell Culture and Transfection Assaysmentioning

confidence: 99%

“…Cell cycle analysis U-87MG cells were transfected with EGFP-spectrin and/or Vpr (wt and mutant) expression plasmids by the calcium phosphate precipitation method (Sawaya et al, 1998). At the indicated times following transfection, the cells were collected.…”

Section: Plasmids Cell Culture and Transfection Assaysmentioning

confidence: 99%

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Molecular mimicry in inducing DNA damage between HIV-1 Vpr and the anticancer agent, cisplatin

et al. 2007

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Section: Introductionmentioning

confidence: 78%

Section: Resultsmentioning

confidence: 99%

Section: Plasmids Cell Culture and Transfection Assaysmentioning

confidence: 99%

Section: Plasmids Cell Culture and Transfection Assaysmentioning

confidence: 99%

Section: Plasmids Cell Culture and Transfection Assaysmentioning

confidence: 99%

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Molecular mimicry in inducing DNA damage between HIV-1 Vpr and the anticancer agent, cisplatin

et al. 2007

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Cdk9 phosphorylates p53 on serine 392 independently of CKII

Claudio

Cui

Ghafouri

et al. 2006

Journal Cellular Physiology

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The tumor suppressor p53 is an important cellular protein, which controls cell cycle progression. Phosphorylation is one of the mechanisms by which p53 is regulated. Here we report the interaction of p53 with another key regulator, cdk9, which together with cyclin T1 forms the positive transcription elongation complex, p-TEFb. This complex cooperates with the HIV-1 Tat protein to cause the phosphorylation of the carboxyl terminal domain (CTD) of RNA polymerase II and this facilitates the elongation of HIV-1 transcription. We demonstrate that cdk9 phosphorylates p53 on serine 392 through their direct physical interaction. Results from protein-protein interaction assays revealed that cdk9 interacts with the C-terminal domain (aa 361-393) of p53, while p53 interacts with the N-terminal domain of cdk9. Transfection and protein binding assays (EMSA and ChIP) demonstrated the ability of p53 to bind and activate the cdk9 promoter. Interestingly, cdk9 phosphorylates serine 392 of p53, which could be also phosphorylated by casein kinase II. Kinase assays demonstrated that cdk9 phosphorylates p53 independently of CKII. These studies demonstrate the existence of a feedback-loop between p53 and cdk9, pinpointing a novel mechanism by which p53 regulates the basal transcriptional machinery.

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p53 and Sp1 cooperate to regulate the expression of epstein–barr viral Zta protein

Chua

Chiu

Lin

et al. 2012

Journal of Medical Virology

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Epstein–Barr virus (EBV) belongs to the gammaherpesvirus family. To produce infectious progeny, EBV reactivates from latency into the lytic cycle by expressing the determinative lytic transactivator, Zta. In the presence of histone deacetylase inhibitor (HDACi), p53 is a prerequisite for the initiation of the EBV lytic cycle by facilitating the expression of Zta. In this study, a serial mutational analysis of Zta promoter (Zp) indicated an important role for the ZID element in responding to HDACi induction and p53 binds to this ZID element together with Sp1, a universal transcription factor. Abolition of the DNA‐binding ability of Sp1 reduces the inducibility of ZID by HDACi and also reduces the amount of p53 binding to ZID. Finally, it was shown that EBV in p53‐positive‐lymphoblastoid cell lines (LCLs) can enter into the lytic cycle spontaneously; however, knockdown of p53 in LCLs leads to retardation of EBV reactivation. J. Med. Virol. 84: 1279–1288, 2012. © 2012 Wiley Periodicals, Inc.

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Cooperative Actions of HIV-1 Vpr and p53 Modulate Viral Gene Transcription

Cited by 90 publications

References 41 publications

Molecular mimicry in inducing DNA damage between HIV-1 Vpr and the anticancer agent, cisplatin

Molecular mimicry in inducing DNA damage between HIV-1 Vpr and the anticancer agent, cisplatin

Cdk9 phosphorylates p53 on serine 392 independently of CKII

p53 and Sp1 cooperate to regulate the expression of epstein–barr viral Zta protein

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