Peripheral protein quality control removes unfolded CFTR from the plasma membrane.
Therapeutic efforts to restore biosynthetic processing of the cystic fibrosis transmembrane conductance regulator lacking the F508 residue (DeltaF508CFTR) are hampered by ubiquitin-dependent lysosomal degradation of nonnative, rescued DeltaF508CFTR from the plasma membrane. Here, functional small interfering RNA screens revealed the contribution of chaperones, cochaperones, and ubiquitin-conjugating and -ligating enzymes to the elimination of unfolded CFTR from the cell surface, as part of a peripheral protein quality-control system. Ubiquitination of nonnative CFTR was required for efficient internalization and lysosomal degradation. This peripheral protein quality-control mechanism probably participates in the preservation of cellular homeostasis by degrading damaged plasma membrane proteins that have escaped from the endoplasmic reticulum quality control or are generated by environmental stresses in situ.
Okiyoneda
Tsukasa
T
Department of Physiology, and Groupe de Recherche Axé sur la Structure des Protéine (GRASP) McGill University, Montreal, Quebec H3G 1Y6, Canada.
Barrière
Hervé
H
Bagdány
Miklós
M
Rabeh
Wael M
WM
Du
Kai
K
Höhfeld
Jörg
J
Young
Jason C
JC
Lukacs
Gergely L
GL
D002462:Cell Membrane / Q000378:metabolism*; D019005:Cystic Fibrosis Transmembrane Conductance Regulator / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D006031:Glycosylation; D050883:HSC70 Heat-Shock Proteins / Q000235:genetics / Q000378:metabolism; D018841:HSP90 Heat-Shock Proteins / Q000378:metabolism; D006367:HeLa Cells; D006706:Homeostasis; D006801:Humans; D008247:Lysosomes / Q000378:metabolism; D018832:Molecular Chaperones / Q000378:metabolism; D050505:Mutant Proteins / Q000737:chemistry / Q000378:metabolism; D011487:Protein Conformation; D017510:Protein Folding; D055550:Protein Stability; D021381:Protein Transport; D034741:RNA, Small Interfering; D011994:Recombinant Proteins / Q000378:metabolism; D013696:Temperature; D044767:Ubiquitin-Protein Ligases / Q000235:genetics / Q000378:metabolism; D057149:Ubiquitinated Proteins / Q000737:chemistry / Q000378:metabolism; D054875:Ubiquitination
C505032:CFTR protein, human; D050883:HSC70 Heat-Shock Proteins; D018841:HSP90 Heat-Shock Proteins; C494371:HSPA8 protein, human; D018832:Molecular Chaperones; D050505:Mutant Proteins; D034741:RNA, Small Interfering; D011994:Recombinant Proteins; D057149:Ubiquitinated Proteins; D019005:Cystic Fibrosis Transmembrane Conductance Regulator; C467728:STUB1 protein, human; D044767:Ubiquitin-Protein Ligases