Muliple sites of action of cycloheximide in addition to inhibition of protein synthesis in Physarum polycephalum.

Abstract

The specificity action of cycloheximide was tested using a cycloheximide resistant mutant of Physarum polycephalum. This resistance has previously been shown to reside with the ribosomes, making cytoplasmic protein synthesis refractile to the action of the drug. We show here that cycloheximide in the mutant strain causes specific alterations in metabolism without influencing the growth rate. These are: 1. lowered specific activity of glutamate dehydrogenase during starvation, 2. alteration of the molecular weight of glutamate dehydrogenase, 3. inhibition of uptake of amino acids from the medium into the internal pools. Possible explanations for these effects of cycloheximide outside of protein synthesis per se are considered. We conclude that cycloheximide may not be considered a specific inhibitor of protein synthesis, and that a causal relationship between protein synthesis and any biological process cannot be claimed unless such specificity is demonstrated in each case, preferably by use of mutants.

• Authors: G Wendelberger-Schieweg, A Hüttermann, F B Haugli
• Journal: Archives of microbiology (Arch Microbiol) Vol. 126 Issue 2 Pg. 109-15 (Jun 1980) ISSN: 0302-8933 [Print] Germany
• PMID: 7436663 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Amino Acids
• Fungal Proteins
• Cycloheximide
• Glucosephosphate Dehydrogenase
• Glutamate Dehydrogenase

Topics

• Amino Acids (metabolism)
• Cell Division (drug effects)
• Cycloheximide (pharmacology)
• Drug Resistance, Microbial
• Fungal Proteins (biosynthesis)
• Glucosephosphate Dehydrogenase (metabolism)
• Glutamate Dehydrogenase (metabolism)
• Mutation
• Physarum (drug effects, genetics, metabolism)