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Free keywords:
ENDOPLASMIC-RETICULUM; YEAST GENES; PROTEINS; IDENTIFICATION;
FLUORESCENCE; EXTRACTION; CYTOPLASM; TRANSPORT; PLATFORM; RECEPTOR
Abstract:
Nuclear pore complexes (NPCs) are very large proteinaceous assemblies that consist of more than 500 individual proteins(1,2). NPCs are essential for nucleocytoplasmic transport of different cellular components, and disruption of the integrity of NPCs has been linked to aging, cancer and neurodegenerative diseases(3-7). However, the mechanism by which membrane-embedded NPCs are turned over is currently unknown. Here we show that, after nitrogen starvation or genetic interference with the architecture of NPCs, nucleoporins are rapidly degraded in the budding yeast Saccharomyces cerevisiae. We demonstrate that NPC turnover involves vacuolar proteases and the core autophagy machinery. Autophagic degradation is mediated by the cytoplasmically exposed Nup159, which serves as intrinsic cargo receptor and directly binds to the autophagy marker protein Atg8. Autophagic degradation of NPCs is therefore inducible, enabling the removal of individual NPCs from the nuclear envelope.
