title: RNA-binding proteins impacting on internal initiation of translation.
abstract: RNA-binding proteins (RBPs) are pivotal regulators of all the steps of gene expression. RBPs govern gene regulation at the post-transcriptional level by virtue of their capacity to assemble ribonucleoprotein complexes on certain RNA structural elements, both in normal cells and in response to various environmental stresses. A rapid cellular response to stress conditions is triggered at the step of translation initiation. Two basic mechanisms govern translation initiation in eukaryotic mRNAs, the cap-dependent initiation mechanism that operates in most mRNAs, and the internal ribosome entry site (IRES)-dependent mechanism activated under conditions that compromise the general translation pathway. IRES elements are cis-acting RNA sequences that recruit the translation machinery using a cap-independent mechanism often assisted by a subset of translation initiation factors and various RBPs. IRES-dependent initiation appears to use different strategies to recruit the translation machinery depending on the RNA organization of the region and the network of RBPs interacting with the element. In this review we discuss recent advances in understanding the implications of RBPs on IRES-dependent translation initiation.
authors.affiliation: Centro de Biología Molecular Severo Ochoa, Consejo Superior de Investigaciones Científicas-Universidad Autónoma de Madrid, Cantoblanco, Madrid 28049, Spain. emartinez@cbm.uam.es.
authors.forename: Encarnación
authors.initials: E
authors.lastname: Martínez-Salas
authors.forename: Gloria
authors.initials: G
authors.lastname: Lozano
authors.forename: Javier
authors.initials: J
authors.lastname: Fernandez-Chamorro
authors.forename: Rosario
authors.initials: R
authors.lastname: Francisco-Velilla
authors.forename: Alfonso
authors.initials: A
authors.lastname: Galan
authors.forename: Rosa
authors.initials: R
authors.lastname: Diaz
mesh_terms: D005786:Gene Expression Regulation; D006801:Humans; D010442:Peptide Chain Initiation, Translational; D014176:Protein Biosynthesis; D012333:RNA, Messenger / Q000235:genetics; D016601:RNA-Binding Proteins / Q000235:genetics* / Q000378:metabolism; D038621:Regulatory Sequences, Ribonucleic Acid / Q000235:genetics*; D012270:Ribosomes / Q000235:genetics
chemical_list: D012333:RNA, Messenger; D016601:RNA-Binding Proteins; D038621:Regulatory Sequences, Ribonucleic Acid