TY - JOUR
T1 - Endocytic trafficking routes of wild type and ΔF508 cystic fibrosis transmembrane conductance regulator
AU - Gentzsch, Martina
AU - Chang, Xiu Bao
AU - Cui, Liying
AU - Wu, Yufeng
AU - Ozols, Victor V.
AU - Choudhury, Amit
AU - Pagano, Richard E.
AU - Riordan, John R.
PY - 2004/6
Y1 - 2004/6
N2 - Intracellular trafficking of cystic fibrosis transmembrane conductance regulator (CFTR) is a focus of attention because it is defective in most patients with cystic fibrosis. ΔF508 CFTR, which does not mature conformationally, normally does not exit the endoplasmic reticulum, but if induced to do so at reduced temperature is short-lived at the surface. We used external epitope-tagged constructs to elucidate the itinerary and kinetics of wild type and ΔF508 CFTR in the endocytic pathway and visualized movement of CFTR from the surface to intracellular compartments. Modulation of different endocytic steps with low temperature (16°C) block, protease inhibitors, and overexpression of wild type and mutant Rab GTPases revealed that surface CFTR enters several different routes, including a Rab5-dependent initial step to early endosomes, then either Rab11-dependent recycling back to the surface or Rab7-regulated movement to late endosomes or alternatively Rab9-mediated transit to the trans-Golgi network. Without any of these modulations ΔF508 CFTR rapidly disappears from and does not return to the cell surface, confirming that its altered structure is detected in the distal as well as proximal secretory pathway. Importantly, however, the mutant protein can be rescued at the plasma membrane by Rab11 overexpression, proteasome inhibitors, or inhibition of Rab5-dependent endocytosis.
AB - Intracellular trafficking of cystic fibrosis transmembrane conductance regulator (CFTR) is a focus of attention because it is defective in most patients with cystic fibrosis. ΔF508 CFTR, which does not mature conformationally, normally does not exit the endoplasmic reticulum, but if induced to do so at reduced temperature is short-lived at the surface. We used external epitope-tagged constructs to elucidate the itinerary and kinetics of wild type and ΔF508 CFTR in the endocytic pathway and visualized movement of CFTR from the surface to intracellular compartments. Modulation of different endocytic steps with low temperature (16°C) block, protease inhibitors, and overexpression of wild type and mutant Rab GTPases revealed that surface CFTR enters several different routes, including a Rab5-dependent initial step to early endosomes, then either Rab11-dependent recycling back to the surface or Rab7-regulated movement to late endosomes or alternatively Rab9-mediated transit to the trans-Golgi network. Without any of these modulations ΔF508 CFTR rapidly disappears from and does not return to the cell surface, confirming that its altered structure is detected in the distal as well as proximal secretory pathway. Importantly, however, the mutant protein can be rescued at the plasma membrane by Rab11 overexpression, proteasome inhibitors, or inhibition of Rab5-dependent endocytosis.
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U2 - 10.1091/mbc.E04-03-0176
DO - 10.1091/mbc.E04-03-0176
M3 - Article
C2 - 15075371
AN - SCOPUS:2542480784
SN - 1059-1524
VL - 15
SP - 2684
EP - 2696
JO - Molecular biology of the cell
JF - Molecular biology of the cell
IS - 6
ER -