Reproductive Cycle of a Retroviridae in a Host Cell

Flow of events during the replication of retroviruses

1. Retrovirus virions enter host cells through interaction between a virally-encoded envelope protein and a cellular receptor.
   
2. Viral RNA is transcribed into a DNA copy by the enzyme reverse transcriptase which is present in the virion.
   
3. The viral DNA copy is integrated into, and becomes a permanent part of, the host genome. This integrated DNA is referred to as a provirus.
   
4. The host cell's transcriptional and translational machinery expresses the viral genes.
   
5. The host RNA polymerase II transcribes the provirus to create new viral RNA, which is then transported out of the nucleus by other cellular processes.
   
6. A fraction of these new RNAs are spliced to allow expression of some genes, while others are left as full-length RNAs.
   
7. Viral proteins are synthesized by the host cell's translational machinery.
   
8. Virions are assembled and bud from the host cell.

Picture extracted: http://gsbs.utmb.edu/microbook/ch042.htm