Over the course of the retrovirus replication cycle, viral cDNA is inserted into host chromosomal DNA to establish the provirus. This process results in a permanent insertion mutation in the host cell genome. Host cells have evolved intracellular factors that block the spread of retroviral infection. Some of these antiviral factors act prior to integration and therefore also block the mutagenic potential of infection.

Several such factors have been identified, including Fv1, the APOBEC3 complex, and TRIM5. These host factors potently block HIV-1 and other retroviruses from establishment of the provirus. Here we will review current understanding of Fv1, APOBEC3, and TRIM5 proteins, with particular emphasis on TRIM5.

Further reading: Retroviruses: Molecular Biology, Genomics and Pathogenesis

Labels: APOBEC3 complex, Fv1, Restriction Factors, TRIM5, TRIM5 protein