The transcription factors FOXO4 and p53 regulate aging, and their deregulation has been linked to several diseases, including cancer. Under stress conditions, cellular senescence is promoted by p53 sequestration and senescence-associated protein p21 transcriptional upregulation induced by interactions between the FOXO4 Forkhead DNA-binding domain and the p53 transactivation domain. However, the molecular details of these interactions remain unclear. Here, we report that these interactions between p53 and FOXO4 domains are highly heterogeneous. The p53 transactivation domain primarily interacts with the region formed by the N-terminal helical bundle of the FOXO4 Forkhead domain but retains a substantial degree of flexibility in the complex. In addition, NMR data-driven molecular simulations suggest that p53 interacts with FOXO4 through multiple binding modes. Overall, our findings not only provide the structural insights into interactions between FOXO4 and p53 but also highlight their potential as targets for developing senolytic compounds.

• MeSH
• forkhead transkripční faktory * metabolismus   chemie   genetika   MeSH
• lidé MeSH
• nádorový supresorový protein p53 * metabolismus   chemie   genetika   MeSH
• proteinové domény MeSH
• proteiny buněčného cyklu * metabolismus   chemie   MeSH
• simulace molekulární dynamiky MeSH
• transkripční faktory * metabolismus   chemie   genetika   MeSH
• vazba proteinů MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• forkhead transkripční faktory * MeSH
• FOXO4 protein, human MeSH Prohlížeč
• nádorový supresorový protein p53 * MeSH
• proteiny buněčného cyklu * MeSH
• TP53 protein, human MeSH Prohlížeč
• transkripční faktory * MeSH

The pre-tetramerization loop (PTL) of the human tumor suppressor protein p53 is an intrinsically disordered region (IDR) necessary for the tetramerization process, and its flexibility contributes to the essential conformational changes needed. Although the IDR can be accurately simulated in the traditional manner of molecular dynamics (MD) with the end-to-end distance (EEdist) unhindered, we sought to explore the effects of restraining the EEdist to the values predicted by electron microscopy (EM) and other distances. Simulating the PTL trajectory with a restrained EEdist , we found an increased agreement of nuclear magnetic resonance (NMR) chemical shifts with experiments. Additionally, we observed a plethora of secondary structures and contacts that only appear when the trajectory is restrained. Our findings expand the understanding of the tetramerization of p53 and provide insight into how mutations could make the protein impotent. In particular, our findings demonstrate the importance of restraining the EEdist in studying IDRs and how their conformations change under different conditions. Our results provide a better understanding of the PTL and the conformational dynamics of IDRs in general, which are useful for further studies regarding mutations and their effects on the activity of p53.

• MeSH
• konformace proteinů MeSH
• lidé MeSH
• magnetická rezonanční spektroskopie MeSH
• nádorový supresorový protein p53 chemie   MeSH
• sekundární struktura proteinů MeSH
• simulace molekulární dynamiky * MeSH
• vnitřně neuspořádané proteiny * chemie   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• nádorový supresorový protein p53 MeSH
• vnitřně neuspořádané proteiny * MeSH

Increased FOXO3 nuclear localization is involved in neuroblastoma chemoresistance and tumor angiogenesis. Accordingly, FOXO3 inhibition is a promising strategy for boosting antitumor immune responses and suppressing FOXO3-mediated therapy resistance in cancer cells. However, no FOXO3 inhibitors are currently available for clinical use. Nevertheless, we have recently identified (4-propoxy)phenylpyrimidinylguanidine as a FOXO3 inhibitor in cancer cells in the low micromolar range. Here, we report the synthesis and structure-activity relationship study of a small library of its derivatives, some of which inhibit FOXO3-induced gene transcription in cancer cells in a submicromolar range and are thus 1 order of magnitude more potent than their parent compound. By NMR and molecular docking, we showed that these compounds differ in their interactions with the DNA-binding domain of FOXO3. These results may provide a foundation for further optimizing (4-propoxy)phenylpyrimidinylguanidine and developing therapeutics for inhibiting the activity of forkhead box (FOX) transcription factors and their interactions with other binding partners.

• Publikační typ
• časopisecké články MeSH