artículo
Activity of the human immunodeficiency virus type 1 cell cycle-dependent internal ribosomal entry site is modulated by IRES trans-acting factors
Fecha
2011Registro en:
10.1093/nar/gkr189
1362-4962
0305-1048
MEDLINE:21482538
WOS:000293919600037
Autor
Vallejos, Maricarmen
Deforges, Jules
Plank, Terra Dawn M.
Letelier, Alejandro
Ramdohr, Pablo
Abraham, Christopher G.
Valiente Echeverria, Fernando
Kieft, Jeffrey S.
Sargueil, Bruno
Lopez Lastra, Marcelo
Institución
Resumen
The 5' leader of the human immunodeficiency virus type 1 (HIV-1) genomic RNA harbors an internal ribosome entry site (IRES) that is functional during the G2/M phase of the cell cycle. Here we show that translation initiation mediated by the HIV-1 IRES requires the participation of trans-acting cellular factors other than the canonical translational machinery. We used 'standard' chemical and enzymatic probes and an 'RNA SHAPE' analysis to model the structure of the HIV-1 5' leader and we show, by means of a footprinting assay, that G2/M extracts provide protections to regions previously identified as crucial for HIV-1 IRES activity. We also assessed the impact of mutations on IRES function. Strikingly, mutations did not significantly affect IRES activity suggesting that the requirement for pre-formed stable secondary or tertiary structure within the HIV-1 IRES may not be as strict as has been described for other viral IRESes. Finally, we used a proteomic approach to identify cellular proteins within the G2/M extracts that interact with the HIV-1 5' leader. Together, data show that HIV-1 IRES-mediated translation initiation is modulated by cellular proteins.