The 3′-Terminal Hexamer Sequence of Classical swine fever virus RNA Plays a Role in Negatively Regulating the IRES-Mediated TranslationReportar como inadecuado




The 3′-Terminal Hexamer Sequence of Classical swine fever virus RNA Plays a Role in Negatively Regulating the IRES-Mediated Translation - Descarga este documento en PDF. Documentación en PDF para descargar gratis. Disponible también para leer online.

The 3′ untranslated region UTR is usually involved in the switch of the translation and replication for a positive-sense RNA virus. To understand the 3′ UTR involved in an internal ribosome entry site IRES-mediated translation in Classical swine fever virus CSFV, we first confirmed the predicted secondary structure designated as SLI, SLII, SLIII, and SLIV by enzymatic probing. Using a reporter assay in which the luciferase expression is under the control of CSFV 5′ and 3′ UTRs, we found that the 3′ UTR harbors the positive and negative regulatory elements for translational control. Unlike other stem loops, SLI acts as a repressor for expression of the reporter gene. The negative cis-acting element in SLI is further mapped to the very 3′-end hexamer CGGCCC sequence. Further, the CSFV IRES-mediated translation can be enhanced by the heterologous 3′-ends such as the polyA or the 3′ UTR of Hepatitis C virus HCV. Interestingly, such an enhancement was repressed by flanking this hexamer to the end of polyA or HCV 3′ UTR. After sequence comparison and alignment, we have found that this hexamer sequence could hypothetically base pair with the sequence in the IRES IIId1, the 40 S ribosomal subunit binding site for the translational initiation, located at the 5′ UTR. In conclusion, we have found that the 3′-end terminal sequence can play a role in regulating the translation of CSFV.



Autor: Shih-Wei Huang, Meng-Yu Chan, Wei-Li Hsu, Chin-Cheng Huang, Ching-Hsiu Tsai

Fuente: http://plos.srce.hr/



DESCARGAR PDF




Documentos relacionados