Topography of bovine papillomavirus E2 protein on the viral genome during the cell cycle.

The multifunctional papillomavirus E2 protein serves important roles in transcriptional activation and genome maintenance and cooperates with the viral E1 helicase for the initiation of viral DNA replication. The bovine papillomavirus genome contains seventeen E2 binding sites, largely concentrated within the long control region, and a single E1 binding site at the origin of viral replication. Using chromatin immunoprecipitation (ChIP) followed by restriction enzyme digestion and PCR, we show that BPV E1 was present only in the region of an active origin of replication and that BPV E2 remained attached to definable segments of the viral genome at specific stages of the cell cycle.

Tumor necrosis factor alpha leads to increased cell surface expression of CXCR4 in SK-N-MC cells.

Both host and viral factors play an important role in the pathogenesis of human immunodeficiency virus (HIV)-associated bran injury. In this study, the authors examined the interactions between tumor necrosis factor (TNF)-alpha, CXCR4, the alpha chemokine receptor, and three HIV isolates, including the T-tropic viruses, HIV-1(MN) and HIV-1(IIIB), and the dual tropic virus, HIV-1(89.6).