. . . "HIV-1 Vpu expression leads to stabilization and upregulation of p53 via inhibiting association of p53 with beta-TrCP and its subsequent ubiquitination" . "HIV-1 Vpu expression results in significant upregulation of phosphorylated p53. Vpu contributes to p53-dependent apoptosis in HIV-1-infected cells" . "upregulates" . "stabilizes" .