title: The protein chaperone Ssa1 affects mRNA localization to the mitochondria.
abstract: Many nuclear-transcribed mRNAs encoding mitochondrial proteins are localized near the mitochondrial outer membrane. A yet unresolved question is whether protein synthesis is important for transport of these mRNAs to their destination. Herein we present a connection between mRNA localization in yeast and the protein chaperone Ssa1. Ssa1 depletion lowered mRNA association with mitochondria while its overexpression increased it. A genome-wide analysis revealed that Ssa proteins preferentially affect mRNAs encoding hydrophobic proteins, which are expected targets for these protein chaperones. Importantly, deletion of the mitochondrial receptor Tom70 abolished the impact of Ssa1 overexpression on mRNAs encoding Tom70 targets. Taken together, our results suggest a role for Ssa1 in mediating localization of nascent peptide-ribosome-mRNA complexes to the mitochondria, consistent with a co-translational transport process.
authors.affiliation: Department of Biology, Technion - Israel Institute of Technology, Haifa 32000, Israel.
authors.forename: Erez
authors.initials: E
authors.lastname: Eliyahu
authors.forename: Chen
authors.initials: C
authors.lastname: Lesnik
authors.forename: Yoav
authors.initials: Y
authors.lastname: Arava
mesh_terms: D000251:Adenosine Triphosphatases / Q000378:metabolism*; D015966:Gene Expression Regulation, Fungal; D018840:HSP70 Heat-Shock Proteins / Q000378:metabolism*; D008928:Mitochondria / Q000378:metabolism*; D033681:Mitochondrial Membrane Transport Proteins / Q000235:genetics / Q000378:metabolism; D000090622:Mitochondrial Precursor Protein Import Complex Proteins; D018832:Molecular Chaperones / Q000378:metabolism*; D012333:RNA, Messenger / Q000378:metabolism*; D012270:Ribosomes / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism*
chemical_list: D018840:HSP70 Heat-Shock Proteins; D033681:Mitochondrial Membrane Transport Proteins; D000090622:Mitochondrial Precursor Protein Import Complex Proteins; D018832:Molecular Chaperones; D012333:RNA, Messenger; D029701:Saccharomyces cerevisiae Proteins; C489039:TOM70 protein, S cerevisiae; D000251:Adenosine Triphosphatases; C095973:SSA1 protein, S cerevisiae