The interactome of retroviral nuclear import and integration.

From a systems biology approach, mammalian viruses offer a unique starting point to study the complex biology of the human cell (1). Our group employs the replication of the human immunodeficiency virus type 1 (HIV-1) in cells to unravel the biology of nuclear import and integration (2). Central is the idea that retroviruses employ cellular proteins as cofactors to achieve important steps in replication. Since identified cofactors as LEDGF/p75 appear to be lentivirus- specific, it follows that differences in lifecycle between lentiviruses and oncoretroviruses may depend on the use of different cofactors. Insight in nuclear import and integration of retroviruses finds applications in treatment/cure of HIV infection and in safer viral vectors for gene therapy.