1. Ribosome binding to the mitochondrial membrane
1.1. Yeast
1.1.1. **2002 George and Lithgow :The nascent polypeptide-associated complex (NAC) promotes interaction of ribosomes with the mitochondrial surface in vivo**"nascent polypeptide-associated complex (NAC) is a peripheral component of cytoplasmic ribosomes, and interacts with nascent chains as they leave the ribosome. Yeast mutants lacking NAC translate polypeptides normally, but have fewer ribosomes associated with the mitochondrial surface. The mutants lacking NAC suffer mitochondrial defects and have decreased levels of proteins like fumarase, normally targeted to mitochondria co-translationally. NAC might contribute to a ribosomal environment in which amino-terminal, mitochondrial targeting sequences can effectively adopt their appropriate conformation. " "the Egd1p/Egd2p complex (NAC) is a peripheral component of cytoplasmic ribosomes, including membrane-associated ribosomes that have not been salt-stripped. Further, NAC is required to pro- mote interaction of ribosomes with the mitochondrial surface in vivo: yeast mutants lacking NAC have less than 10% of wild-type levels of mitochondria-bound ribosomes and have a defect in respiratory function. NAC function is required to maintain e⁄cient targeting of some mitochondrial proteins, including fumarase, malate deh"
1.1.2. **1972 Kellems and Butow : Cytoplasmic-type 80 S Ribosomes Associated with Yeast Mitochondria: I. EVIDENCE FOR RIBOSOME BINDING SITES ON YEAST MITOCHONDRIA**
1.2. Human
1.3. Mammals
1.3.1. **1998 Crowley and Payne : Ribosome Binding to Mitochondria Is Regulated by GTP and the Transit Peptide** By using spectral measurements, analysis of mitochondrial associated RNA, and electron microscopy, we demonstrated that ribosomes stably bind to purified rat liver mitochondria in vitro. Binding of ribosomes to mitochondria was markedly reduced by GTP and nearly abolished by the non-hydrolyzable GTP analogue, guanosine-5 -[thio]-triphosphate (GTP S), but was only modestly reduced by GDP or ATP and unaffected by CTP. The initial rate of GTP hydrolysis by mitochondria was increased by ribosomes, whereas the rate of ATP hydrolysis by mitochondria was not af- fected. Ribosomes programmed with mRNA for 92 amino acids of the N terminus of mitochondrial malate dehydrogenase bound to mitochondria, but unlike unpro- grammed rat liver ribosomes, neither GTP nor GDP dis- rupted binding; however, GTP S did. These data show that receptors specific for ribosomes are present on the mitochondrial membrane, and a GTP-dependent proc- ess mediates this binding. The presence of a nascent chain alters these binding characteristics.
2. Co-translational import itself
2.1. Yeast
2.1.1. **1993 Fujiki Verner : Coupling of cytosolic protein synthesis and Mitochondrial Protein Import in Yeast ** : COXIV-DHFR system + antifolate methotrexate (TMP analogue) Article assez compliquer à lire, pas très claire.
2.2. Human
2.3. Mammals
3. mRNA close to the mitochondrial membrane
3.1. Yeast
3.1.1. **2002 Marc et al : Genome-wide analysis sis of mRNAs targeted to yeast mitochondria.**. --> "Two main classes of mRNAs encoding mitochondrial proteins were identified, in which mRNA molecules were associated with mitochondrion-bound polysomes or with free cytosolic polysomes. In addition, we have shown that mRNAs located close to mitochondria had a 3′-UTR conferring mitochondrion- targeting properties. Finally, we observed that the two extreme classes of mRNA molecules encoding mitochondrial protein were related to genes of different origins: the mRNA molecules present in mitochondrion-bound polysomes were transcribed from genes with known homologues identified in bacteria, whereas the mRNA molecules present in free cytosolic polysomes were transcribed from genes of eukaryotic origin." Exemple of gene where the 3'UTR were tested for localisation are ATM1, COQ4, MRF1mRNA