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Endoplasmic Reticulum-Associated Degradation Of Pca1p, A Polytopic Protein, Via Interaction With The Proteasome At The Membrane, Nathan Smith, David J. Adle, Miaoyun Zhao, Xiaojuan Quin, Heejeong Kim, Jaekwon Lee

Department of Biochemistry: Faculty Publications

Endoplasmic reticulum-associated degradation (ERAD) plays a critical role for destruction of terminally misfolded proteins at the secretory pathway. The system also regulates expression levels of several proteins such as Pca1p, a cadmium exporter in yeast. To gain better insight into the mechanisms underlying ERAD of Pca1p and other polytopic proteins by the proteasome in the cytosol, our study determined the roles for the molecular factors of ERAD in dislodging Pca1p from the ER. Inactivation of the 20S proteasome leads to accumulation of ubiquitinylated Pca1p in the ER membrane, suggesting a role for the proteasome in extraction of Pca1p from the …