HIV-1 Rev/Crm1 Contacts in a Cellular Context
HIV-1 Rev is a protein responsible for transporting partially spliced and fully unspliced HIV-1 RNA from the nucleus. HIV-1 hijacks the cellular nuclear export factor Crm1, recruiting it to partially spliced and fully unspliced HIV-1 RNA, which contains a structured RNA element called the Rev Response Element, or RRE. Once in the cytoplasm, the full length HIV-1 RNA can be used for translation of late viral proteins, or can be packaged into virions. The structure of the HIV-1 nuclear export complex has been solved using electron microscopy. The model determined from the EM structure has two copies of Crm1 surrounding a hexamer of Rev bound to the RRE. However, Crm1 has always been thought to work as a monomer in vivo. This work shows evidence for a presence of a Crm1 dimer in vivo, in conditions with and without the other components of the HIV-1 nuclear export complex present.