About Cycloheximide (Actidione)

Cycloheximide is an inhibitor of protein biosynthesis in eukaryotic organisms, produced by the bacterium Streptomyces griseus. Cycloheximide exerts its effect by interfering with the translocation step in protein synthesis (movement of two tRNA molecules and mRNA in relation to the ribosome) thus blocking translational elongation. Cycloheximide is widely used in biomedical research to inhibit protein synthesis in eukaryotic cells studied in vitro (i.e. outside of organisms). It is inexpensive and works rapidly. Its effects are rapidly reversed by simply removing it from the culture medium.Since cycloheximide is an effective inhibitor of protein biosynthesis in eukaryotes only, it may be used to distinguish between proteins translated in the mitochondria and proteins translated in the cytosol. mRNA translated in cytosol or ER from mRNA derived from the nucleus will not be expressed in the presence of cycloheximide. Conversely, translation using mitochondrial ribosomes is unaffected by cycloheximide, and mitochondrial genes will continue to be expressed. Cycloheximide can be used as an experimental tool in molecular biology to determine the half-life of a protein. Treating cells with cycloheximide in a time-course experiment followed by Western blotting of the cell lysates for the protein of interest can show differences in protein half-life. Cycloheximide treatment provides the ability to observe the half-life of a protein without confounding contributions from transcription or translation.
It is used as a plant growth regulator to stimulate ethylene production. It is used as a rodenticide and other animal pesticide. It is also used in media to detect unwanted bacteria by suppressing yeasts and molds in beer fermentation.