CHARACTERIZATION OF VIRUS HOST-INTERACTIONS THAT REGULATE HIV-1 REPLICATION Der Naturwissenschaftlichen Fakultät der Friedrich-Alexander-Universität Erlangen-Nürnberg zur Erlangung des Doktorgrades vorgelegt von Jörg Votteler aus Hof/Saale Als Dissertation genehmigt von der Naturwissenschaftlichen Fakultät der Universität Erlangen-Nürnberg Tag der mündlichen Prüfung: 05.02.2009 Vorsitzender der Prüfungskommission: Prof. Dr. Eberhard Bänsch Erstberichterstatter: Prof. Dr. U. Schubert Zweitberichterstatter: PD Dr. R. Slany ABSTRACT Retroviruses like the human immunodeficiency virus type 1 (HIV-1) are obligate cellular parasites that depend on host cell factors for their replication. The aim of this study was to characterize two specific cases of these numerous virus-host interactions. First, the previously identified interaction between the cellular peptidyl-prolyl cis/trans isomerase cyclophilin A (CypA) and the HIV-1 accessory protein Vpr was investigated on the molecular level. HIV-1 Vpr induces G cell-cycle arrest and apoptosis in infected cells, and it facilitates the transport of 2the pre-integration complex into the nucleus of non-dividing cells. This multi-functional protein interacts with a variety of cellular factors, among them CypA.