We show from our current e periments that Gag Ser487 phosphorylation has a significant impact on p6 Vpr binding. Vpr is a non structural viral protein that is incorporated into virions and possesses several charac teristic features selleckchem Enzalutamide and functions that are known to play im portant roles in HIV 1 replication and disease progression. The presence of a functional Vpr in viral particles is necessary for the efficient translocation of the pre integration comple into the nucleus and subse quent infection of primary monocytes macrophages and other non dividing cells. Vpr also has a crucial role in viral replication, apoptosis, cell cycle arrest and in the down regulation of immune activation.

Many Vpr functions are carried out by virion associated Vpr, suggesting that the incorporation of Vpr into virus particles is an important event not only in HIV 1 replication but also in HIV 1 mediated cyto pathogenesis. Several previous reports have indicated that p6 is phos phorylated during HIV 1 infection. However, these studies did not undertake any detailed investigation of the biological significance of this phosphorylation event through biochemical or structural analyses. Our current computer assisted structural modeling and AlphaScreen homogenous pro imity assays have revealed that the phosphorylated Gag at Ser487 binds more stably to Vpr whereas there was no significant difference in the inter action of Gag p6 with Ali , consistent with previous reports. The phosphorylation of Ser487 can create another hydrogen bond between Gag Ser487 and Vpr Gln44.

In consistent with this data a previous study indi cated that the site specific deletion of Gln44 resulted in the significant reduction of Vpr incorporation into virions. We also demonstrate that Gag phosphorylation at Ser487 affects Vpr incorporation and this process could be mediated by Gln44 residue of Vpr. We show in our current study that Gag phosphoryl ation on Ser487 itself does not affect the binding affinity of Gag with Ali . However, resultant Vpr interaction to Gag may hinder the Ali Gag interaction at the LYP nL motif. This may eliminate Ali from nascent VLP and impeded its ability to function in HIV 1 release in PTAP deficient strains of HIV. On the other hands, Ali also interacts with the nucleocapsid domain of HIV 1 Gag in addition to binding the LYP nL motif, there by linking Gag to components of ESCRT III.

Therefore, further analysis is needed to fully understand the molecular link between Gag phosphorylation and virus release through the Ali LYP nL pathway. We further e plored Batimastat the physiological significance of Vpr incorporation into virions. Our current results clearly demonstrate that the inhibition of aPKC mediated Vpr incorporation prominently reduces the viral infectivity in MDMs. These results together indicate that Gag phos phorylation by aPKC plays a crucial role in the HIV 1 infection of macrophages.