Pharmacological modulation of the interaction between tubulin and a SARS-CoV-2 protein

Abstract

1p.-6 fig.The cytoskeleton is the main communication/transport route within cells and many viruses abuse on this cellular machine to fulfil their cycle. We initially identified the interaction of a SARS-CoV-2 protein with tubulin using a proteomic analysis. We next confirmed the interaction and identified the viral protein domain involved through in vitro co-immunoprecipitation assays and analytical ultracentrifugation experiments. Then, we focused on unveiling the molecular mechanism of the interaction to determine if the SARS-CoV-2 protein promote a stable microtubule assembly (as roads for motors) or induce microtubule dynamics (as main force generation for transport). We have combined biochemical, biophysical and structural studies to determine the ratio of protein-protein interaction and the resulting effect on tubulin assembly. We have found that this protein domain is able to promote microtubule depolymerization into rings and tubulin assembly into non-functional filaments likely because a preference for tubulin curved-conformation. Importantly, this effect is not dependent on nucleotide or nucleotide hydrolysis. Finally, tubulin is a well-known target in cancer diseases and there are four of the seven tubulin druggable sites exploited on chemotherapy. Hence, we have analyzed the ability of microtubule stabilizing (MSA) and destabilizing agents (MDA) on disrupting the interaction of SARS-CoV-2 protein with tubulin. We have found that MSAs keep microtubule structures even in the presence of the viral protein, while the effect of MDAs varies depending on their mechanism of action.This research work was funded by Ministerio de Ciencia e Innovación and CSIC. It was also funded by the European Commission – NextGenerationEU (Regulation EU2020/2094), through CSIC's Global Health Platform (PTI Salud Global).Peer reviewe