Mutational analysis of HIV-1 viral protein U at Ser52 and Ser56 among the HIV-1 infected patients of Manipur

BackgroundPhosphorylation by Casein kinase 2 at two conserved seryl residues, Ser52 and Ser56 at the cytoplasmic domain of HIV-1 Viral protein U (Vpu) are essential for inducing CD4 degradation. This study is conducted to investigate the variability of HIV-1 viral protein unique particularly at amino-acid position Ser52 and Ser56 among the HIV infected individuals in the northeastern region of India.Materials and methodsBlood samples from 90 HIV-1 infected patients of Manipur have been studied by viral amplification and sequencing at vpu gene of HIV-1. For analysis of amino acid variation at Ser52 and Ser56, nucleic acid sequences were translated into amino acid and aligned with reference strain of HIV-1. Phylogenetic tree was also inferred among the studied samples.ResultsThe results revealed that 93% of HIV-1 infected individuals harbored virus with conserved serine at both amino acid positions 52 and 56 of vpu which were known to have the ability to induce CD4 degradation while 1% harbored viral mutation at both Ser52 and Ser56, replaced by asparagine which has been predicted to may have lost the ability to induce CD4 degradation. Moreover, 5% and 1% of HIV-1 infected individuals were found to be infected with mutated virus at ser52 and ser56 of vpu respectively.ConclusionThe overall finding of this study reveals that seryl residue of vpu at Ser52 and Ser56 was highly conserved among the HIV-1 infected individuals of the study population.