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Protein folding state-dependent sorting at the Golgi apparatus

In eukaryotic cells, organelle-specific protein quality control (PQC) is critical for maintaining cellular homeostasis. Despite the Golgi apparatus being the major protein processing and sorting site within the secretory pathway, how it contributes to PQC has remained largely unknown. Using differen...

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Detalles Bibliográficos
Autores principales: Hellerschmied, Doris, Serebrenik, Yevgeniy V., Shao, Lin, Burslem, George M., Crews, Craig M.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: The American Society for Cell Biology 2019
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6743468/
https://www.ncbi.nlm.nih.gov/pubmed/31166830
http://dx.doi.org/10.1091/mbc.E19-01-0069
Descripción
Sumario:In eukaryotic cells, organelle-specific protein quality control (PQC) is critical for maintaining cellular homeostasis. Despite the Golgi apparatus being the major protein processing and sorting site within the secretory pathway, how it contributes to PQC has remained largely unknown. Using different chemical biology-based protein unfolding systems, we reveal the segregation of unfolded proteins from folded proteins in the Golgi. Quality control (QC) substrates are subsequently exported in distinct carriers, which likely contain unfolded proteins as well as highly oligomerized cargo that mimic protein aggregates. At an additional sorting step, oligomerized proteins are committed to lysosomal degradation, while unfolded proteins localize to the endoplasmic reticulum (ER) and associate with chaperones. These results highlight the existence of checkpoints at which QC substrates are selected for Golgi export and lysosomal degradation. Our data also suggest that the steady-state ER localization of misfolded proteins, observed for several disease-causing mutants, may have different origins.