HIV-1 MATRIX PROTEIN P17 IS TRANSLOCATED INTO THE CELL-NUCLEUS AND BINDS TO VIRAL GENOMIC RNA

The role of matrix protein p17 of the human immunodeficiency virus in the HIV morphogenesis has been demonstrated. In a pulse-chase experime nt the gag p55 polyprotein was shown to be proteolytically processed 2 h after its synthesis. In so doing the p17 protein penetrated into th e nuclei while the p24 protein remained in the cytoplasm. To elucidate the role of the p17 protein in the intracellular of viral genomic RNA , HIV-infected Jurkat-tat limphoblastoid cells were fractionated into nuclear, membraneous, and cytosolic fractions. Viral complexes were im munoprecipitated with monoclonal antibodies raised against p17 or othe r gag proteins, and then used for RNA isolation. This RNA was analyzed , like the supernatant RNA; by slot and blot hybridization. All the vi rus-specific RNA localized in the nuclei, including the full-size geno mic RNA, proved to be associated with the p17 protein. It is suggested that p17 transfers the viral genomic RNA from the nucleus to the site of virus assembly, thus being a key factor in virus morphogenesis.