Deletion of HOG1 leads to Osmosensitivity in starvation-induced, but not rapamycin-dependent Atg8 degradation and proteolysis: further evidence for different regulatory mechanisms in yeast autophagy.
The mechanisms of regulation of autophagy are still obscure. In mammalian liver, starvation-induced autophagic proteolysis is regulated by the cellular hydration state in a microtubule- and p38(MAPK)-dependent way. Recent work shows that in yeast, loss of Hog1, the yeast orthologue of p38(MAPK), leads to osmosensitivity of starvation-induced autophagy (Prick et al., Biochem J 2006; 394:153-161), pointing to an evolutionarily conserved mechanism. In this addendum further experiments from hog1Delta yeast cells are shown, which support the hypothesis that starvation- and rapamycin-induced autophagy processes differ in their susceptibility to osmotic stress. The potential mechanisms are discussed.
Prick
Tanja
T
Division of Gastroenterology, Hepatology and Infectious Diseases, Heinrich-Heine-University, Düsseldorf, Germany. tapr@arcor.de
Thumm
Michael
M
Häussinger
Dieter
D
Vom Dahl
Stephan
S
D000818:Animals; D001343:Autophagy / Q000502:physiology*; D000071190:Autophagy-Related Protein 8 Family; D017353:Gene Deletion; D015966:Gene Expression Regulation, Fungal; D006801:Humans; D008869:Microtubule-Associated Proteins / Q000378:metabolism*; D020928:Mitogen-Activated Protein Kinases / Q000235:genetics* / Q000502:physiology; D008954:Models, Biological; D011489:Protein Denaturation / Q000187:drug effects / Q000502:physiology*; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics* / Q000378:metabolism* / Q000502:physiology; D020123:Sirolimus / Q000494:pharmacology; D014882:Water-Electrolyte Balance / Q000235:genetics / Q000502:physiology*
C113757:ATG8 protein, S cerevisiae; D000071190:Autophagy-Related Protein 8 Family; D008869:Microtubule-Associated Proteins; D029701:Saccharomyces cerevisiae Proteins; C088589:HOG1 protein, S cerevisiae; D020928:Mitogen-Activated Protein Kinases; D020123:Sirolimus