ICT - MILSTEIN   05483
INSTITUTO DE CIENCIA Y TECNOLOGIA "DR. CESAR MILSTEIN"
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Role of non-coding sequences in Arenavirus mRNAs translation
Autor/es:
FOSCALDI SABRINA; ALEJANDRA DANTUONO; LOPEZ, NORA
Lugar:
Granada
Reunión:
Congreso; XV International Conference on Negative Strand Viruses; 2013
Institución organizadora:
NSV OC
Resumen:
The genome of Tacaribe virus (TCRV),
prototype of the New World arenaviruses, comprises two RNA segments each
encoding two proteins in an ambisense orientation. TCRV coding sequences are
expressed from subgenomic messenger RNAs (mRNAs) transcribed from the 3´
regions of the genomes and antigenomes. Viral mRNAs contain cap structure and
short stretches of non-viral nucleotides upstream of viral 5? untranslated
regions (UTR). Also, they lack a 3? poly(A) tail, exhibiting a 3? non-coding region
predicted to form stable secondary hairpin structures with a suspected role in
translation. To analyze the contribution of non-coding sequences to TCRV mRNAs translation,
we generated a synthetic transcript mimicking the TCRV Nucleoprotein (N) mRNA,
which contains the Firefly Luciferase (LUC) open reading frame. Mutant mRNAs
were designed to carry modifications in either the 5? or the 3? non-coding
sequence. Translation from these virus-like mRNAs in transfected cells was
evidenced by LUC activity. Deletion of the complete 5? UTR caused loss of LUC
activity, while significantly reduced levels of reporter gene activity were
associated to deletion of the 3? non-coding region, suggesting that both 5? and
3? non-coding sequences stimulate virus-like mRNA translation. Studies are
underway to define the role of viral proteins and to identify structural
signatures in viral mRNAs that may modulate their translation.