Protein Vpr 105 VPR_HV2SB R ORF protein vpr Stimulates gene expression driven by the HIV-2 LTR. Prevents infected cells from undergoing mitosis and proliferating, by inducing arrest or delay in the G2 phase of the cell cycle. Cell cycle arrest creates a favourable environment for maximizing viral expression and production (By similarity). Viral protein R MTEAPAEFPPEDGTPPREPGDEWVIEILREIKEEALKHFDPRLLTALGYYIYTRHGDTLEGARELIRVLQRALFTHFRAGCGHSRIGQPRGRNPLSAIPTPRNMQ