Within the virion, adenovirus DNA associates with the virus-encoded, protamine-like structural protein pVII. Whether this association is organized, and how genome packaging changes during infection and subsequent transcriptional activation is currently unclear. Here, we combined RNA-seq, MNase-seq, ChIP-seq, and single genome imaging during early adenovirus infection to unveil the structure- and time-resolved dynamics of viral chromatin changes as well as their correlation with gene transcription. Our MNase mapping data indicates that the adenoviral genome is arranged in precisely positioned nucleoprotein particles with nucleosome-like characteristics, that we term adenosomes. We identified 238 adenosomes that are positioned by a DNA sequence code and protect about 60-70 bp of DNA. The incoming adenoviral genome is more accessible at early gene loci that undergo additional chromatin de-condensation upon infection. Histone H3.3 containing nucleosomes specifically replaces pVII at distinct genomic sites and at the transcription start sites of early genes. Acetylation of H3.3 is predominant at the transcription start sites and precedes transcriptional activation. Based on our results, we propose a central role for the viral pVII nucleoprotein architecture, which is required for the dynamic structural changes during early infection, including the regulation of nucleosome assembly prior to transcription initiation. Our study thus may aid the rational development of recombinant adenoviral vectors exhibiting sustained expression in gene therapy.
Zika virus (ZIKV) remains a pressing global health concern due to its association with congenital Zika syndrome and the current lack of approved antiviral therapies. In this study, we evaluated the antiviral activity of three novel thiazolidinedione derivatives, GQ-402, GQ-396, and ZKC-10, against ZIKV in vitro and investigated their potential molecular targets through in silico analysis. GQ-402 exhibited the highest antiviral potency, with an IC50 of 15.7 µM, while ZKC-10 achieved the most substantial reduction in viral RNA levels, as determined by RT-qPCR. Molecular docking studies identified GQ-396 as the top-ranked inhibitor of the NS2B-NS3 protease and NS5 RNA-dependent RNA polymerase, suggesting distinct mechanisms of action among the compounds. These findings highlight the therapeutic potential of thiazolidinedione derivatives and underscore the need for further investigation to develop effective treatments for ZIKV infection.
Integrase is a key protein during HIV-1 replication as it catalyzes the integration of viral DNA into the host DNA. After several decades of research, highly potent and selective active site inhibitors have emerged. The new challenge is now to develop molecules with an original mode of action, targeting integrase out of its catalytic site. During a previous study, we developed an in vitro assay to monitor the interaction between HIV-1 integrase and one of its cellular partners, GCN2. This AlphaLISA-based assay was validated as a platform for chemical modulator screening. In the present study, we used a library of natural products from the Developmental Therapeutics Program (NIH) to identify novel chemical leads. The best modulators were characterized and a structure–activity relationship study was initiated with a limited number of derivatives. We found that most inhibitors were tricylic or tetraclyclic molecules, with the most potent belonging to the anthracyclines/anthraquinones. Of note, several molecules exhibited interesting cellular activities and may be suitable for further optimization.