The cellular protein MCM3AP is required for inhibition of cellular DNA synthesis by the IE86 protein of human cytomegalovirus.

Like all DNA viruses, human cytomegalovirus (HCMV) infection is known to result in profound effects on host cell cycle. Infection of fibroblasts with HCMV is known to induce an advance in cell cycle through the G(0)-G(1) phase and then a subsequent arrest of cell cycle in early S-phase, presumably resulting in a cellular environment optimum for high levels of viral DNA replication whilst precluding replication of cellular DNA. Although the exact mechanisms used to arrest cell cycle by HCMV are unclear, they likely involve a number of viral gene products and evidence points to the ability of the virus to prevent licensing of cellular DNA synthesis.

Retinoic acid-induced glandular differentiation of the oesophagus.

Background: Retinoic acid (RA) is a powerful differentiation agent. Barrett's oesophagus occurs when duodeno-gastro-oesophageal reflux causes squamous epithelium (SE) tissue to become columnar epithelium tissue by an unknown mechanism. The bile acid lithocholic acid (LCA) competes for the retinoid X receptor retinoid binding site.

Solving mysteries of DNA replication and frog cloning.

Compared to sperm nuclei, nuclei from adult somatic cells replicate inefficiently in frog egg extract. In this issue of Cell, Lemaitre et al. (2005) show that pre-exposure of erythrocyte nuclei to a mitotic extract removes this difference, reorganizes the chromatin into shorter loops, and allows replication at much shorter intervals along the DNA.