Broad anti-pathogen potential of DEAD box RNA helicase eIF4A-targeting rocaglates

Inhibition of eukaryotic initiation factor 4A has been proposed as a strategy to fight pathogens. Rocaglates exhibit the highest specificities among eIF4A inhibitors, but their anti-pathogenic potential has not been comprehensively assessed across eukaryotes. In silico analysis of the substitution patterns of six eIF4A1 aa residues critical to rocaglate binding, uncovered 35 variants. Molecular docking of eIF4A:RNA:rocaglate complexes, and in vitro thermal shift assays with select recombinantly expressed eIF4A variants, revealed that sensitivity correlated with low inferred binding energies and high melting temperature shifts. In vitro testing with silvestrol validated predicted resistance in Caenorhabditis elegans and Leishmania amazonensis and predicted sensitivity in Aedes sp., Schistosoma mansoni, Trypanosoma brucei, Plasmodium falciparum, and Toxoplasma gondii. Our analysis further revealed the possibility of targeting important insect, plant, animal, and human pathogens with rocaglates. Finally, our findings might help design novel synthetic rocaglate derivatives or alternative eIF4A inhibitors to fight pathogens.

A nucleotide signature for identification of Aglaia stellatopilosa Pannell

Members of the genus Aglaia have been reported to contain bioactive phytochemicals. The genus, belonging to the Meliaceae family, is represented by at least 120 known species of woody trees or shrubs in the tropical rain forest. As some of these species are very similar in their morphology, taxonomic identification can be difficult. A reliable and definitive molecular method which can identify Aglaia to the level of the species will hence be useful in comparing the content of specific bioactive compounds between the species of this genus. Here, we report the analysis of DNA sequences in the internal transcribed spacer (ITS) of the nuclear ribosomal DNA and the observation of a unique nucleotide signature in the ITS that can be used for the identification of Aglaia stellatopilosa. The nucleotide signature consists of nine bases over the length of the ITS sequence (654 bp). This uniqueness was validated in 37 samples identified as Aglaia stellatopilosa by an expert taxonomist, whereas the nucleotide signature was lacking in a selection of other Aglaia species and non-Aglaia genera. This finding suggests that molecular typing could be utilized in the identification of Aglaia stellatopilosa.