title: Structural insights into viral IRES-dependent translation mechanisms.
abstract: A diverse group of viruses subvert the host translational machinery to promote viral genome translation. This process often involves altering canonical translation initiation factors to repress cellular protein synthesis while viral proteins are efficiently synthesized. The discovery of this strategy in picornaviruses, which is based on the use of internal ribosome entry site (IRES) elements, opened new avenues to study alternative translational control mechanisms evolved in different groups of RNA viruses. IRESs are cis-acting RNA sequences that adopt three-dimensional structures and recruit the translation machinery assisted by a subset of translation initiation factors and various RNA binding proteins. However, IRESs present in the genome of different RNA viruses perform the same function despite lacking conservation of primary sequence and secondary RNA structure, and differing in host factor requirement to recruit the translation machinery. Evolutionary conserved motifs tend to preserve sequences impacting on RNA structure and RNA-protein interactions important for IRES function. While some motifs are found in various picornavirus IRESs, others occur only in one type reflecting specialized factor requirements. This review is focused to describe recent advances on the principles and RNA structure features of picornavirus IRESs.
authors.affiliation: Centro de Biología Molecular Severo Ochoa, Consejo Superior de Investigaciones Científicas - Universidad Autónoma de Madrid, Nicolas Cabrera 1, 28049 Madrid, Spain.
authors.forename: Gloria
authors.initials: G
authors.lastname: Lozano
authors.affiliation: Centro de Biología Molecular Severo Ochoa, Consejo Superior de Investigaciones Científicas - Universidad Autónoma de Madrid, Nicolas Cabrera 1, 28049 Madrid, Spain. Electronic address: emartinez@cbm.csic.es.
authors.forename: Encarnación
authors.initials: E
authors.lastname: Martínez-Salas
mesh_terms: D005786:Gene Expression Regulation; D016679:Genome, Viral; D006801:Humans; D000067556:Internal Ribosome Entry Sites; D009690:Nucleic Acid Conformation; D010849:Picornaviridae / Q000235:genetics / Q000472:pathogenicity / Q000502:physiology; D014176:Protein Biosynthesis; D012328:RNA Viruses / Q000235:genetics* / Q000472:pathogenicity / Q000502:physiology*; D012367:RNA, Viral / Q000737:chemistry / Q000378:metabolism; D014764:Viral Proteins / Q000378:metabolism
chemical_list: D000067556:Internal Ribosome Entry Sites; D012367:RNA, Viral; D014764:Viral Proteins