Methionine is a regulator of starvation-induced proteolysis in Tetrahymena.
The ciliate Tetrahymena thermophila responds to starvation by drastically increasing the rate of proteolysis. The response was reversed by resuspending the cells in a defined growth medium. Among the components of this medium only amino acids were active in inhibiting proteolysis. One amino acid, methionine, accounted for at least 75% of the effect of the complete medium, strongly indicating that in Tetrahymena methionine is the main regulator of step-down proteolysis, a process generally connected with autophagy in eukaryotic cells. The fact that one amino acid has such a drastic effect should make the system well suited for further investigations of the regulation of this process.
Grinde
B
B
Department of Biology, University of Oslo, Norway.
Jonassen
T O
TO
D000596:Amino Acids / Q000494:pharmacology; D000625:Aminooxyacetic Acid / Q000494:pharmacology; D000818:Animals; D001343:Autophagy / Q000187:drug effects; D003513:Cycloheximide / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D006868:Hydrolysis; D008715:Methionine / Q000031:analogs & derivatives / Q000494:pharmacology*; D011506:Proteins / Q000378:metabolism*; D013217:Starvation / Q000378:metabolism*; D013768:Tetrahymena / Q000378:metabolism*
D000596:Amino Acids; D011506:Proteins; D000625:Aminooxyacetic Acid; D003513:Cycloheximide; D008715:Methionine