The HIV-1 matrix protein p17 interferes with the PI3Kinase-AKT pathway in p17R-expressing cell lines

The HIV-1 p17 is a structural protein that may also act as a virokine able toderegulate several immune functions through a interaction with a cellular surfacereceptor(p17R). Here we demonstrated that, in different p17R-expressing cell lines,p17 can interfere with the PI3-kinase-AKT pathway through AKT inactivation. Thisevidence was enforced by the finding that p17 induces an upregulation of PTEN, aspecific AKT-phosphatase, and a decrease of PI3-kinase activity. To better definethe intracellular pathway involved by the p17 activity we also evaluated the level ofMAPK (ERK1/2) phosphorylation and we showed that p17 can promote MAPKdephosphorylation probably though a tyrosine-phosphatase activation. These datasupport the possibility that p17 may hamper physiological activation pathwaysthrough the p17/p17R interaction.