Mensah, T.N.A.; Shroff, A.; Nazarko, T.Y. Ubiquitin-Binding Autophagic Receptors in Yeast: Cue5 and Beyond. Autophagy 2023, 1–5, doi:10.1080/15548627.2023.2196878.
Mensah, T.N.A.; Shroff, A.; Nazarko, T.Y. Ubiquitin-Binding Autophagic Receptors in Yeast: Cue5 and Beyond. Autophagy 2023, 1–5, doi:10.1080/15548627.2023.2196878.
Mensah, T.N.A.; Shroff, A.; Nazarko, T.Y. Ubiquitin-Binding Autophagic Receptors in Yeast: Cue5 and Beyond. Autophagy 2023, 1–5, doi:10.1080/15548627.2023.2196878.
Mensah, T.N.A.; Shroff, A.; Nazarko, T.Y. Ubiquitin-Binding Autophagic Receptors in Yeast: Cue5 and Beyond. Autophagy 2023, 1–5, doi:10.1080/15548627.2023.2196878.
Abstract
The selectivity in selective autophagy pathways is achieved via the selective autophagy receptors (SARs) – proteins that bind a ligand on the substrate to be degraded and the Atg8-family protein on the growing autophagic membrane, phagophore, effectively bridging them. In mammals, the most common ligand of SARs is ubiquitin, a small protein modifier that tags substrates for their preferential degradation by autophagy. Consequently, the most common SARs are the ubiquitin-binding SARs, such as SQSTM1/p62 (sequestosome 1). Surprisingly, there is only one SAR of this type in yeast – Cue5, which acts as a receptor for aggrephagy and proteaphagy – pathways that remove the ubiquitinated protein aggregates and proteasomes, respectively. However, recent studies described the ubiquitin-dependent autophagic pathways that do not require Cue5, e.g. stationary phase lipophagy for intracellular lipid droplets and nitrogen starvation-induced mitophagy for mitochondria. What is the role of ubiquitin in these pathways? Here, we propose that the ubiquitinated lipid droplets and mitochondria are recognized by the alternative ubiquitin-binding SARs. Our analysis identifies the proteins that could potentially fulfill this role in yeast. We think that matching of the ubiquitin-dependent (but Cue5-independent) autophagic pathways with the ubiquitin-and-Atg8-binding proteins enlisted here might uncover the novel ubiquitin-binding SARs in yeast.
Biology and Life Sciences, Cell and Developmental Biology
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