Leite, J. | Search bioRxiv

bioRxiv2023

Unveiling the antiviral capabilities of targeting Human Dihydroorotate Dehydrogenase against SARS-CoV-2

The urgent need for effective treatments against emerging viral diseases, driven by drug-resistant strains and new viral variants, remains critical. We focus on inhibiting the human dihydroorotate dehydrogenase (HsDHODH), one of the enzymes in charge of pyrimidine nucleotide synthesis. This strategy could impede viral replication without provoking resistance. We evaluated quinone-based compounds, discovering potent HsDHODH inhibition (low nanomolar IC50) and promising in vitro anti-SARS-CoV-2 activity (low micromolar EC50). These compounds exhibited low toxicity, indicating potential for further development. Additionally, we employed computational tools like molecular docking and QSAR models to analyze protein-ligand interactions. These findings represent a significant step forward in the search for effective antiviral treatments and have great potential to impact the development of new broad-spectrum antiviral drugs.

biochemistry↗

bioRxiv2018

Flow-independent accumulation of motor-competent non-muscle myosin II in the contractile ring is essential for cytokinesis

Cytokinesis in animal cells requires the assembly of a contractile actomyosin ring, whose subsequent constriction physically separates the two daughter cells. Non-muscle myosin II (myosin) is essential for cytokinesis, but the role of its motor activity remains poorly defined. Here, we examine cytokinesis in C. elegans one-cell embryos expressing myosin motor mutants generated by genome editing. Motor-dead myosin, which is capable of binding F-actin, does not support cytokinesis, and embryos co-expressing motor-dead and wild-type myosin are delayed in cytokinesis. Partially motor-impaired myosin also delays cytokinesis and renders contractile rings more sensitive to reduced myosin levels. Thus, myosin motor activity, rather than its ability to cross-link actin filaments, drives contractile ring assembly and constriction. We further demonstrate that myosin motor activity is required for long-range cortical actin flows, but that flows per se play a minor role in contractile ring assembly. Our results suggest that flow-independent recruitment of motor-competent myosin to the cell equator is both essential and rate-limiting for cytokinesis.

cell biology↗