Cytomegaloviruses nuclear drill

The capsids of herpesvirus are too large to pass through the nuclear pore complex. That they are seen in the nucleus suggests that they are able to penetrate the nuclear membrane, but the precise mechanism they employ has remained unclear. In August 2 Science Walter Muranyi and colleagues from Ludwig-Maximilians-Universität München, Germany, show that cytomegaloviruses recruit cellular kinases to dissolve the nuclear lamina and penetrate the nuclear envelope (Science 2002, 297:854-857).

Muranyi et al. subcloned a series of candidate open reading frames from murine CMV and identified M50 — predicted to be a type II transmembrane protein 35 kD in size (p35). They observed that M50/p35 recruited cellular protein kinase C for phosphorylation and dissolution of the nuclear lamina. In addition, they showed that M50/p35 inserted into the inner nuclear membrane and was aggregated by a second viral protein, M53/p38, to form a herpesvirus capsid docking site.

The authors suggest ...