Using peptides to study the interaction between the p53 tetramerization domain and HIV‐1 tat

Gabizon, Ronen; Mor, Michal; Rosenberg, Masha M.; Britan, Lena; Hayouka, Zvi; Kotler, Moshe; Shalev, Deborah E.; Friedler, Assaf

doi:10.1002/bip.20919

Cited by 24 publications

(44 citation statements)

References 47 publications

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“…We next examined whether p53 interacts directly with Tat protein. Direct interaction of p53 and Tat has been controversial (33)(34)(35), and we could not find any evidence of a direct interaction between p53 and Tat in coimmunoprecipitation (co-IP) assays or yeast two-hybrid analysis (data not shown). These data suggested that another factor(s) may be involved in p53-mediated Tat suppression rather than direct interactions between the two molecules.…”

Section: Hiv-1 Infection Activates P53 Which Inhibits Tat Functionmentioning

confidence: 81%

p53-Derived Host Restriction of HIV-1 Replication by Protein Kinase R-Mediated Tat Phosphorylation and Inactivation

Yoon

Kim

Byeon

et al. 2015

J Virol

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Tumor suppressor p53 has been suggested to be a host restriction factor against HIV-1 replication, but the detailed molecular mechanism has remained elusive for decades. Here, we demonstrate that p53-mediated HIV-1 suppression is attributed to double-stranded RNA (dsRNA)-dependent protein kinase (PKR)-mediated HIV-1 trans-activator (Tat) phosphorylation and inactivation. p53 silencing significantly enhanced HIV-1 replication in infected cells. Ectopic expression of p53 suppressed Tat activity, which was rescued by PKR silencing. In addition, ectopic expression of PKR abolished Tat activity in p53 ؊/؊ and eIF2␣ CA cells. Finally, we found that HIV-1 infection activates p53, followed by the induction and activation of PKR. PKR directly interacted with HIV-1 Tat and phosphorylates the first exon of Tat exclusively at five Ser/Thr residues (T23, T40, S46, S62, and S68), which inhibits Tat-mediated provirus transcription in three critical steps: (i) phosphorylation near the arginine-rich motif (ARM) inhibits Tat translocation into the nucleus, (ii) accumulation of Tat phosphorylation abolishes Tat-Tat-responsive region (TAR) binding, and (iii) Tat phosphorylation at T23 and/or T40 obliterates the Tat-cyclin T1 interaction. These five Ser/Thr sites on Tat were highly conserved in HIV-1 strains prevalent in Europe and the United States. Taken together, our findings indicate that p53-derived host restriction of HIV-1 replication is likely attributable, at least in part, to a noncanonical p53/PKR/Tat phosphorylation and inactivation pathway in HIV-1 infection and AIDS pathogenesis. IMPORTANCEHIV-1-mediated disease progression to AIDS lasts for years to decades after primary infection. Host restriction and associated viral latency have been studied for several decades. p53 has been suggested as an important host restriction factor against HIV-1 replication. However, the detailed molecular mechanism is still unclear. In the present study, we found that the p53-mediated HIV-1 restriction is attributed to a p53/PKR/Tat-inactivation pathway. HIV-1 infection activated p53, which subsequently induced PKR expression and activation. PKR directly phosphorylated Tat exclusively at five specific Ser/Thr residues, which was accompanied by significant suppression of HIV-1 replication. Accumulation of Tat phosphorylation at these sites inhibited Tat function by blocking Tat nuclear localization, Tat binding to TAR, and Tat-cyclin T1 interaction. Our findings provide a better understanding of the p53-derived host restriction mechanism against HIV-1 replication in AIDS pathogenesis and may contribute to further research focusing on the investigation of potential therapeutic targets for HIV-1. Human immunodeficiency virus type I (HIV-1) encodes a highly conserved trans-activator (Tat) protein, which is essential for viral replication and disease progression (1). Although Tat is a potent trans-activator in HIV-1 replication, HIV-1-mediated disease progression lasts for decades after primary infection (2). Host restriction mechanism...

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Section: Hiv-1 Infection Activates P53 Which Inhibits Tat Functionmentioning

confidence: 81%

p53-Derived Host Restriction of HIV-1 Replication by Protein Kinase R-Mediated Tat Phosphorylation and Inactivation

Yoon

Kim

Byeon

et al. 2015

J Virol

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“…The existence of large unstructured protein domains has recently been evidenced by NMR, for soluble proteins. It seems that unstructured protein domain, can fold upon contact with other proteins, as shown by the example of natively unfolded HIV-1 Tat protein and the tetramerization domains of the cellular tumor suppressor protein p53 [27]. It is therefore conceivable that the fine nanostructure of material surface can help folding protein domains that are unstructured in solution.…”

Section: 3mentioning

confidence: 99%

Protein conformational changes induced by adsorption onto material surfaces: an important issue for biomedical applications of material science

Ballet¹,

Boulangé²,

Bréchet³

et al. 2010

Bulletin of the Polish Academy of Sciences: Technical Sciences

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Abstract. Protein adsorption on solid surfaces is a widespread phenomenon of large biological and biotechnological significance. Conformational changes are likely to accompany protein adsorption, but are difficult to evidence directly. Nevertheless they have important consequences, since the partial unfolding of protein domains can expose hitherto hidden amino acids. This remodeling of the protein surface can trigger the activation of molecular complexes such as the blood coagulation cascade or the innate immune complement system. In the case of extracellular matrix, it can also change the way cells interact with the material surfaces and result in modified cell behavior. In this review, we present direct and indirect evidences that support the view that some proteins change their conformation upon adsorption. We also show that both physical and chemical methods are needed to study the extent and kinetics of protein conformational changes. In particular, AFM techniques and cryo-electron microscopy provide useful and complementary information. We then review the chemical and topological features of both proteins and material surfaces in relation with protein adsorption. Mutating key amino acids in proteins changes their stability and this is related to material-induced conformational changes, as shown for instance with insulin. In addition, combinatorial methods should provide valuable information about peptide or antibody adsorption on well-defined material surfaces. These techniques could be combined with molecular modeling methods to decipher the rules governing conformational changes associated with protein adsorption.

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“…The effect was shown to be dependent on the p53 phosphorylation state [29]. Other proteins reported to bind to p53CTD are E3 ligases [30], [31], tumor suppressors [32] and viral proteins [33], [34].…”

Section: Introductionmentioning

confidence: 98%

Specific Recognition of p53 Tetramers by Peptides Derived from p53 Interacting Proteins

et al. 2012

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Oligomerization plays a major role in regulating the activity of many proteins, and in modulating their interactions. p53 is a homotetrameric transcription factor that has a pivotal role in tumor suppression. Its tetramerization domain is contained within its C-terminal domain, which is a site for numerous protein-protein interactions. Those can either depend on or regulate p53 oligomerization. Here we screened an array of peptides derived from proteins known to bind the tetrameric p53 C-terminal domain (p53CTD) and identified ten binding peptides. We quantitatively characterized their binding to p53CTD using fluorescence anisotropy. The peptides bound tetrameric p53CTD with micromolar affinities. Despite the high charge of the binding peptides, electrostatics contributed only mildly to the interactions. NMR studies indicated that the peptides bound p53CTD at defined sites. The most significant chemical shift deviations were observed for the peptides WS100B(81–92), which bound directly to the p53 tetramerization domain, and PKCα(281–295), which stabilized p53CTD in circular dichroism thermal denaturation studies. Using analytical ultracentrifugation, we found that several of the peptides bound preferentially to p53 tetramers. Our results indicate that the protein-protein interactions of p53 are dependent on the oligomerization state of p53. We conclude that peptides may be used to regulate the oligomerization of p53.

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Using peptides to study the interaction between the p53 tetramerization domain and HIV‐1 tat

Cited by 24 publications

References 47 publications

p53-Derived Host Restriction of HIV-1 Replication by Protein Kinase R-Mediated Tat Phosphorylation and Inactivation

p53-Derived Host Restriction of HIV-1 Replication by Protein Kinase R-Mediated Tat Phosphorylation and Inactivation

Protein conformational changes induced by adsorption onto material surfaces: an important issue for biomedical applications of material science

Specific Recognition of p53 Tetramers by Peptides Derived from p53 Interacting Proteins

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