HIV life cycle

HIV life cycle. Small arrowheads, viral entry to integration. Curved arrows, early replication. Double-headed arrows, late replication. (1) Adsorption to CD4 receptor and either CXCR4 or CCR5 co-receptor. (2) Fusion. (3) Uncoating of viral genomic RNA dimer. (4) Reverse transcription (RT, reverse transcriptase). (5) Formation of pre-integration complex (PIC). (6) Nuclear import of PIC. (7) Integration of proviral DNA into host genome. (8) Transcription of early multiply spliced mRNAs. (9) Translation of early regulatory proteins, Tat and Rev. (10) Nuclear import of Tat and Rev. Tat increases transcription of viral mRNAs. (11) Rev mediates export of singly spliced and unspliced viral mRNAs. (12) Translation of viral structural proteins. (13) Assembly at the plasma membrane of viral genomic RNA, proteins, and cellular factors including tRNA(Lys3), the obligate primer for reverse transcription. (14) Viral budding. (15) Viral maturation. Cellular factors involved in viral transcription: RNA polIII, TRBP, NF-B and PCAF (see text).