Vac8 controls vacuolar membrane dynamics during different autophagy pathways in \(\textit {Saccharomyces cerevisiae}\)

  • The yeast vacuole is a vital organelle, which is required for the degradation of aberrant intracellular or extracellular substrates and the recycling of the resulting nutrients as newly available building blocks for the cellular metabolism. Like the plant vacuole or the mammalian lysosome, the yeast vacuole is the destination of biosynthetic trafficking pathways that transport the vacuolar enzymes required for its functions. Moreover, substrates destined for degradation, like extracellular endocytosed cargoes that are transported by endosomes/multivesicular bodies as well as intracellular substrates that are transported via different forms of autophagosomes, have the vacuole as destination. We found that non-selective bulk autophagy of cytosolic proteins as well as the selective autophagic degradation of peroxisomes (pexophagy) and ribosomes (ribophagy) was dependent on the armadillo repeat protein Vac8 in \(\textit {Saccharomyces cerevisiae}\). Moreover, we showed that pexophagy and ribophagy depended on the palmitoylation of Vac8. In contrast, we described that Vac8 was not involved in the acidification of the vacuole nor in the targeting and maturation of certain biosynthetic cargoes, like the aspartyl-protease Pep4 (PrA) and the carboxy-peptidase Y (CPY), indicating a role of Vac8 in the uptake of selected cargoes. In addition, we found that the hallmark phenotype of the \(\it vac\Delta\) strain, namely the characteristic appearance of fragmented and clustered vacuoles, depended on the growth conditions. This fusion defect observed in standard glucose medium can be complemented by the replacement with oleic acid or glycerol medium. This complementation of vacuolar morphology also partially restores the degradation of peroxisomes. In summary, we found that Vac8 controlled vacuolar morphology and activity in a context- and cargo-dependent manner.

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Metadaten
Author:Fahd BoutoujaGND, Christian M. StiehmGND, Christina ReidickGND, Thomas MastalskiGND, Rebecca BrinkmeierGND, Fouzi El MagraouiGND, Harald W. PlattaGND
URN:urn:nbn:de:hbz:294-70991
DOI:https://doi.org/10.3390/cells8070661
Parent Title (English):Cells
Publisher:MDPI
Place of publication:Basel
Document Type:Article
Language:English
Date of Publication (online):2020/04/05
Date of first Publication:2019/06/30
Publishing Institution:Ruhr-Universität Bochum, Universitätsbibliothek
Tag:Open Access Fonds
Vac8; autophagy; bulk autophagy; pexophagy; ribophagy; vacuole
Volume:8
Issue:7, Article 661
First Page:661-1
Last Page:661-18
Note:
Article Processing Charge funded by the Deutsche Forschungsgemeinschaft (DFG) and the Open Access Publication Fund of Ruhr-Universität Bochum.
Institutes/Facilities:Institut für Biochemie und Pathobiochemie, Abteilung für Systembiochemie
Dewey Decimal Classification:Naturwissenschaften und Mathematik / Biowissenschaften, Biologie, Biochemie
open_access (DINI-Set):open_access
faculties:Fakultät für Chemie und Biochemie
Licence (English):License LogoCreative Commons - CC BY 4.0 - Attribution 4.0 International