LEDGF/p75 functions downstream from preintegration complex formation to effect gene-specific HIV-1 integration
| Autor: | Peter Cherepanov, Alan Engelman, Ming-Chieh Shun, Paul Kellam, Janet E. Daigle, Nick Vandegraaff, Nidhanapati K. Raghavendra, Siobhan M. Hughes |
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| Jazyk: | angličtina |
| Rok vydání: | 2007 |
| Předmět: |
Virus Integration
HIV integration In Vitro Techniques Cell Line PSIP1 Mice Transcription (biology) Consensus Sequence Genetics Animals Humans Promoter Regions Genetic Gene Adaptor Proteins Signal Transducing Reporter gene Binding Sites biology Base Sequence Integrases DNA Integrase Leukemia Virus Murine CpG site biology.protein HIV-1 Intercellular Signaling Peptides and Proteins CpG Islands Gene Deletion Developmental Biology Research Paper Transcription Factors |
| Popis: | LEDGF/p75 directly interacts with lentiviral integrase proteins and can modulate their enzymatic activities and chromosomal association. A novel genetic knockout model was established that allowed us for the first time to analyze HIV-1 integration in the absence of LEDGF/p75 protein. Supporting a crucial role for the cofactor in viral replication, HIV-1 vector integration and reporter gene expression were significantly reduced in LEDGF-null cells. Yet, integrase processed the viral cDNA termini normally and maintained its local target DNA sequence preference during integration. Preintegration complexes extracted from knockout cells moreover supported normal levels of DNA strand transfer activity in vitro. In contrast, HIV-1 lost its strong bias toward integrating into transcription units, displaying instead increased affinity for promoter regions and CpG islands. Our results reveal LEDGF/p75 as a critical targeting factor, commandeering lentiviruses from promoter- and/or CpG island-proximal pathways that are favored by other members of Retroviridae. Akin to yeast retrotransposons, disrupting the lentiviral targeting mechanism significantly perturbs overall integration. |
| Databáze: | OpenAIRE |
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