Chemical Composition,Antimicrobial, Nitric Oxide Inhibition and Cytotoxic Activity of Essential Oils from Zanthoxylum acanthopodium DC. Leaves and Stems from Vietnam

This study was aimed to investigate the chemical composition and biological activities of leaf and stem essential oils of Zanthoxylum acanthopodium DC. from Vietnam. Their chemical composition was analyzed by GC/MS. Antimicrobial activities were evaluated by microdilution broth assay. Anti-inflammatory activity was evaluated by the ability to inhibit nitric oxide production in macrophage cells. Cytotoxic activity was evaluated using the sulforhodamine B assay on three human cancer cell lines. Forty-four compounds were identified in the leaf oil, among which dehydroaromadendrane (23.4 %), (E)-carpacin (17.6 %), 2-tridecanone (12.2 %), and 9-methyl-2-decanone (11.8 %) were the most abundant. The stem oil contained fifty-five identified constituents, mainly γ-gurjunene (51.1 %) and butyl acetate (11.8 %). Both oils exhibited inhibitory effects on three bacterial strains, namely S. aureus, E. coli, P. aeruginosa and a fungal strain C. albican, while showed insignificant effects on B. subtilis, L. fermentum, and S. enterica. Both oils showed weak NO production inhibition in LPS-induced RAW264.7 cells, but exhibited potent cytotoxic activity against all three tested cell lines SK-LU-1, MCF-7, and HepG2 with the IC₅₀ values ranging from 16.03±0.77 to 35.60±1.62 μg/mL. This is the first report on the antimicrobial, anti-inflammatory and cytotoxic activities of essential oils from the leaves and stems of Z. acanthopodium.     

Relationship between the GTPase,metal-binding,and dimerization activities of <Emphasis Type="Italic">E. coli</Emphasis> HypB

Biosynthesis of the metallocenter in the active site of the [NiFe] hydrogenase enzyme requires the accessory protein HypB, which is a metal-binding GTPase. In this study, the interplay between the individual activities of Escherichia coli HypB was examined. The full-length protein undergoes nucleotide-responsive dimerization that is disrupted upon mutation of L242 and L246 to alanine. This mutant HypB is monomeric under all of the conditions investigated but the inability of L242A/L246A HypB to dimerize does not abolish its GTPase activity and the monomeric protein has metal-binding behavior similar to that of wild-type HypB. Furthermore, expression of L242A/L246A HypB in vivo results in hydrogenase activity that is approximately half of the activity produced by the wild-type control, suggesting that dimerization of HypB does not have a critical role in the hydrogenase maturation pathway. In contrast, the GTPase activity of HypB is modulated by metal loading of the protein. These results provide insight into the role of HypB in hydrogenase biosynthesis.     

A manually curated network of the PML nuclear body interactome reveals an important role for PML-NBs in SUMOylation dynamics

Promyelocytic Leukaemia Protein nuclear bodies (PML-NBs) are dynamic nuclear protein aggregates. To gain insight in PML-NB function, reductionist and high throughput techniques have been employed to identify PML-NB proteins. Here we present a manually curated network of the PML-NB interactome based on extensive literature review including database information. By compiling ''the PML-ome'', we highlighted the presence of interactors in the Small Ubiquitin Like Modifier (SUMO) conjugation pathway. Additionally, we show an enrichment of SUMOylatable proteins in the PML-NBs through an in-house prediction algorithm. Therefore, based on the PML network, we hypothesize that PML-NBs may function as a nuclear SUMOylation hotspot.