RT Journal Article
SR Electronic
T1 Recycling of nutrient transporters from yeast endosomes is regulated by ubiquitinated Ist1
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 2021.06.19.449106
DO 10.1101/2021.06.19.449106
A1 Kamilla ME. Laidlaw
A1 Grant Calder
A1 Chris MacDonald
YR 2021
UL http://biorxiv.org/content/early/2021/06/19/2021.06.19.449106.abstract
AB Trafficking of cell surface membrane proteins through a dynamic network of endomembrane compartments ensures correct cellular function. Upon internalisation, many surface proteins are either degraded or recycled back to the plasma membrane. Although these pathways control many biological processes, the precise regulatory features and division of labour between interconnected pathways is unclear. Using the budding yeast Saccharomyces cerevisiae, our work suggests retrograde recycling via the trans-Golgi Network (TGN) of cargoes like yeast synaptobrevins (Snc1 / Snc2), that rely on cargo ubiquitination, is distinct from endosomal trafficking of nutrient transporters. We provide evidence that nutrient transporters internalise to, and upon deubiquitination recycle from, endosomes marked by Vps4 and Ist1. A genetic screen for this recycling pathway previously implicated the ESCRT-III associated factor Ist1, suggesting Ist1 functionally defines yeast recycling endosomes. We demonstrate Ist1 ubiquitination affects its endosomal recruitment and ability to promote recycling. Finally, we reveal the ubiquitin-binding adaptor Npl4 and the essential ATPase Cdc48 are also involved in recycling. Our work suggests features of endosomal recycling are evolutionarily conserved.Competing Interest StatementThe authors have declared no competing interest.