Analysis of single and multiple mutants constructs for human cytomegalovirus UL97 gene and its relationship with the phosphorylation activity of pUL97 kinase

SANCHEZ PUCH,SI; MATHET, VL; PORTA,M; CUESTAS,ML; OUBIÑA,JR; VIDELA,CM; SALOMÓN,HE

Antiviral Research

Elsevier

Lugar: Netherlands; Año: 2009 vol. 84 p. 194 - 198

0166-3542

In this study we determined the presence of multiple amino acidic substitutions in the protein encoded by the UL97 gene of an HCMV strain recovered of an immunocompromised patient. The double mutant M460V/D605E is related to resistance to antiviral therapy with GCV and seven of twelve amino acidic changes (F102L, D118V, M330T, T400A, R507P, C511R y I533V) are reported herein for the first time. Our results suggest that the aspartic acid-to-glutamic acid substitution at codon 605 may be associated with a natural polymorphism of the UL97 gene, and not with a positive selection pressure exerted by the antiviral drug. We also could determinate that GCV resistance due to the M460V mutation in the UL97 HCMV gene is not offset by a second mutation at codon D605E. Our results show that when two mutations related to GCV resistance are detected simultaneously in the same HCMV genome, such viral resistance might be enhanced in comparison to the single mutants studied separately. We also analyzed for first time the phosphotransferase activity of a triple UL97 mutant, M460V/A594P/D605E, in relation to its ability to phosphorylate GCV. Expression of a truncated protein was an unexpectedly event and chromatographic profile obtained for this truncated protein, was compatible with that of a resistant phenotype.