The major human immunodeficiency virus type 2 (HIV-2) packaging signal is present on all HIV-2 RNA species: Cotranslational RNA encapsidation and limitation of Gag protein confer specificity
Sdc. Griffin et al., The major human immunodeficiency virus type 2 (HIV-2) packaging signal is present on all HIV-2 RNA species: Cotranslational RNA encapsidation and limitation of Gag protein confer specificity, J VIROLOGY, 75(24), 2001, pp. 12058-12069
Deletion of a region of the human immunodeficiency virus type 2 (HIV-2) 5'
leader RNA reduces genomic RNA encapsidation to about 5% that of wild-type
virus with no defect in viral protein production but severely limits virus
spread in Jurkat T cells, indicating that this region contains a major cis-
acting encapsidation signal, or psi (psi). Being upstream of the major spli
ce donor, it is present on all viral transcripts. We have shown that HIV-2
selects its genomic RNA for encapsidation cotranslationally, rendering wild
-type HIV-2 unable to encapsidate vector RNAs in trans. Virus with psi dele
ted, however, encapsidates an HIV-2 vector, demonstrating competition for G
ag protein. HIV-2 overcomes the lack of packaging signal location specifici
ty by two novel mechanisms, cotranslational packaging and competition for l
imiting Gag polyprotein.