Relevance of the N-terminal and major hydrophobic domains of non-structural protein 3A in the replicative process of a DNA-launched Foot-and-mouth Disease Virus replicon.

LOTUFO, CECILIA; WILDA, MAXIMILIANO; GIRALDEZ ADRIAN; GRIGERA, PABLO; MATTION, NORA

ARCHIVES OF VIROLOGY

SPRINGER WIEN

Lugar: Viena; Año: 2018

0304-8608

doi.org/10.1007/s00705-018-3795-9A foot-and-mouth disease virus (FMDV) DNA-launched reporter replicon, containing the Luciferase gene, was used to assess the impact of non-structural (NS) protein 3A on viral replication. Independent deletions within both the N terminal [amino acid (aa) residues 6 to 24] and the central hydrophobic (HR, aa 59 to 76) regions of FMDV NS protein 3A were engineered and Luciferase activity in lysates of control and mutated replicon-transfected cells was measured. Both triple alanine replacements of the N terminal triplet Arg 18- His 19 -Glu 20 and a single alanine substitution of the highly charged Glu 20 residue resulted in 70-80% reduction in Luciferase activity when compared with wild type controls. Alanine substitution of the 17 aa present in the central HR, on the other hand, resulted in complete inhibition of Luciferase activity and in the accumulation of the mutated 3A within the cell nuclei according to immunofluorescence analysis. Our results suggest that both, the aa sequence around the most likely exposed hydrophilic E20 residue at the N terminus of the protein and the central hydrophobic tract located between aa 59 and 76, are of mayor relevance in maintaining a functional 3A and preventing its mislocalizing into the cell nucleus.