Protein synthesis in yeast

Fujiki, M. Vemer, K. (1993). Coupling of cytosolic protein synthesis and mitochondrial protein import in yeast. J. Biol. Chem. 268, 1914-1920. 

Although there is a 5-fold difference between the sizes of the mitochondrial genomes of yeast (84 kb) and mammals (16 kb), the number of proteins synthesized within mitochondria is similar. Proteins produced by mammalian mitochondria are those involved in electron-transport and oxidative-phosphorylation systems. These include cytochrome b, three subunits of cytochrome oxidase, one subunit of ATPase, and six subunits of NADH dehydrogenase. Apart from these differences, protein synthesis in mitochondria follows the same steps and mechanisms as those in the cytoplasm. 

Gaynor, E. C., Mondesert, G., Grimme, S.J., Reed, S. I., Orlean, P., and Emr, S. D. (1999). MCD4 encodes a conserved endoplasmic reticulum membrane protein essential for glycosylphosphatidylinositol anchor synthesis in yeast. Mol. Biol. CeU 10, 627-648. 

Baciphelacin is toxic to HeLa cells and a study of its mechanism of action revealed that it was a potent inhibitor of protein synthesis (ref.121). A 50% inhibition of protein synthesis in HeLa cells was found at a concentration around 10" M (0.042 ig/ml). This compound is unusual and interesting because it blocks translation only in animal cells and not in plant, yeast or Escherichia coli systems. Translation inhibitors are usually blockers of eukaryotic and/or prokaryotic systems not animal cells only. In a study of related compounds 4-acetyl-6,8-dihydroxy-5-methyl-3,4-dihydroisocoumarin was found to block translation in HeLa cells but not in yeast cells. Interestingly, the saturated... 

Auxins are also involved in so-called long term responses which may be more directly gene-mediated responses. Auxins stimulate and sustain mRNA and protein synthesis to form enzymes that catalyze the production of cell wall materials, sugars, and other cellular components. Applied lAA has induced mRNA and protein synthesis in Avena coleoptiles (16), yeast cells (17), pea stem sections (18), and bean endocarp (19). Artichoke tuber disks responded to exogenously applied lAA with growth and a substantial amount of new RNA and protein synthesis. When the metabolic inhibitors actinomycin D and 8-azaguanine were added simultaneously with lAA, effects of the auxin were negated (20). 

In contrast, the toxic agents cycloheximideemetine,amd puromycin, inhibit protein synthesis in animal cells as well as in protozoa and yeast. A rational design of antibacterial agents might well concentrate on drugs which act by the same mechanism as chloramphenicol. 

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