INVESTIGADORES
ALVAREZ Diego Ezequiel
congresos y reuniones científicas
Título:
Role of dengue virus 3-untranslated region on translation and RNA stability.
Autor/es:
ANA L. DE LELLA EZCURRA; DIEGO E. ALVAREZ; ANDREA V. GAMARNIK
Lugar:
Villa Carlos Paz
Reunión:
Congreso; XXXVII Reunión Nacional de la SAIB; 2002
Institución organizadora:
Sociedad Argentina de Investigación Bioquímica y Biología Molecular
Resumen:
Dengue virus (DV) is a positive stranded RNA virus responsible of serious illness in humans.
During the viral life cycle the genome is used as a template for
protein synthesis, RNA amplification, and encapsidation. The regulation
of these processes is mainly mediated by signals present at the 5 and
3 untranslated regions (UTRs) of the viral RNA by mechanisms not well
understood. To study the role of the UTRs on translation we build a
simple construct encoding luciferase flaked by the 5 and 3UTRs of DV.
The 5UTR is 100 nucleotides long and has a cap structure while the
3UTR has four defined domains: A1, A2, A3 and A4, lacking a poly(A)
tail. By in vitro transcription we synthesized the RNAs with deletions
of each domain of the 3UTR and studied the translation efficiencies
after microinjections into Xenopus laevis oocytes or
transfections into BHK and mosquito cells. The deletion of A2 and A3
domains decrease 10 fold the efficiency of translation, suggesting an
important role of the 3UTR on translation initiation or RNA stability.
To investigate this last possibility we developed an assay to study
the half-life of radiolabeled RNAs into oocytes. The stability of the
wild type RNA was very similar to the RNA carrying the A2A3 deletions.
These results suggest that the 3UTR could be directly involved in the
translation process. To understand the molecular mechanism of
translation stimulation we are using mobility shift and UV crosslinking
assays to study RNA-RNA and RNA-protein interactions that involve both
the 3 and the 5 UTRs.