Journal
JOURNAL OF CELL SCIENCE
Volume 124, Issue 8, Pages 1339-1350Publisher
COMPANY OF BIOLOGISTS LTD
DOI: 10.1242/jcs.076406
Keywords
Autophagy; General stress response; Mitochondrial dynamics; Mitophagy; WHI2
Categories
Funding
- Deutsche Forschungsgemeinschaft DFG [RE-1575/1-1]
- Goethe University [EXC 115]
- [SFB 594]
Ask authors/readers for more resources
Dysfunctional mitochondria show a reduced capacity for fusion and, as mitochondrial fission is maintained, become spatially separated from the intact network. By that mechanism, dysfunctional mitochondria have been proposed to be targeted for selective degradation by mitophagy, thereby providing a quality control system for mitochondria. In yeast, conflicting results concerning the role of mitochondrial dynamics in mitophagy have been reported. Here, we investigate the effects on mitophagy of altering mitochondrial fission and fusion, using biochemical, as well as fluorescence-based, assays. Rapamycin-induced mitophagy was shown to depend upon the autophagy-related proteins Atg11, Atg20 and Atg24, confirming that a selective type of autophagy occurred. Both fragmentation of mitochondria and inhibition of oxidative phosphorylation were not sufficient to trigger mitophagy, and neither deletion of the fission factors Dnm1, Fis1, Mdv1 or Caf4 nor expression of dominant-negative variants of Dnm1 impaired mitophagy. The diminished mitophagy initially observed in a Delta fis1 mutant was not due to the absence of Fis1 but rather due to a secondary mutation in WHI2, which encodes a factor reported to function in the general stress response and the Ras-protein kinase A (PKA) signaling pathway. We propose that, in yeast, mitochondrial fission is not a prerequisite for the selective degradation of mitochondria, and that mitophagy is linked to the general stress response and the Ras-PKA signaling pathway.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available