TY - JOUR
T1 - Recycling and resensitization of the neurokinin 1 receptor
T2 - Influence of agonist concentration and Rab GTPases
AU - Roosterman, Dirk
AU - Cottrell, Graeme S.
AU - Schmidlin, Fabien
AU - Steinhoff, Martin
AU - Bunnett, Nigel W.
PY - 2004/7/16
Y1 - 2004/7/16
N2 - Substance P (SP) induces endocytosis and recycling of the neurokinin 1 receptor (NK1R) in endothelial cells and spinal neurons at sites of inflammation and pain, and it is thus important to understand the mechanism and function of receptor trafficking. We investigated how the SP concentration affects NK1R trafficking and determined the role of Rab GTPases in trafficking. NK1R trafficking was markedly influenced by the SP concentration. High SP (10 nM) induced translocation of the NK1R and β-arrestin 1 to perinuclear sorting endosomes containing Rab5a, where NK1R remained for >60 min. Low SP (1 nM) induced translocation of the NK1R to early endosomes located immediately beneath the plasma membrane that also contained Rab5a and β-arrestin 1, followed by rapid recycling of the NK1R. Overexpression of Rab5a promoted NK1R translocation to perinuclear sorting endosomes, whereas the GTP binding-deficient mutant Rab5aS34N caused retention of the NK1R in superficial early endosomes. NK1R translocated from superficial early endosomes to recycling endosomes containing Rab4a and Rab11a, and Rab11aS25N inhibited NK1R recycling. Rapid NK1R recycling coincided with resensitization of SP-induced Ca 2+ mobilization and with the return of surface SP binding sites. Resensitization was minimally affected by inhibition of vacuolar H +-ATPase and phosphatases but was markedly suppressed by disruption of Rab4a and Rab11a. Thus, whereas β-arrestins mediate NK1R endocytosis, Rab5a regulates translocation between early and sorting endosomes, and Rab4a and Rab11a regulate trafficking through recycling endosomes. We have thus identified a new function of Rab5a as a control protein for directing concentration-dependent trafficking of the NK1R into different intracellular compartments and obtained evidence that Rab4a and Rab11a contribute to G-protein-coupled receptor recycling from early endosomes.
AB - Substance P (SP) induces endocytosis and recycling of the neurokinin 1 receptor (NK1R) in endothelial cells and spinal neurons at sites of inflammation and pain, and it is thus important to understand the mechanism and function of receptor trafficking. We investigated how the SP concentration affects NK1R trafficking and determined the role of Rab GTPases in trafficking. NK1R trafficking was markedly influenced by the SP concentration. High SP (10 nM) induced translocation of the NK1R and β-arrestin 1 to perinuclear sorting endosomes containing Rab5a, where NK1R remained for >60 min. Low SP (1 nM) induced translocation of the NK1R to early endosomes located immediately beneath the plasma membrane that also contained Rab5a and β-arrestin 1, followed by rapid recycling of the NK1R. Overexpression of Rab5a promoted NK1R translocation to perinuclear sorting endosomes, whereas the GTP binding-deficient mutant Rab5aS34N caused retention of the NK1R in superficial early endosomes. NK1R translocated from superficial early endosomes to recycling endosomes containing Rab4a and Rab11a, and Rab11aS25N inhibited NK1R recycling. Rapid NK1R recycling coincided with resensitization of SP-induced Ca 2+ mobilization and with the return of surface SP binding sites. Resensitization was minimally affected by inhibition of vacuolar H +-ATPase and phosphatases but was markedly suppressed by disruption of Rab4a and Rab11a. Thus, whereas β-arrestins mediate NK1R endocytosis, Rab5a regulates translocation between early and sorting endosomes, and Rab4a and Rab11a regulate trafficking through recycling endosomes. We have thus identified a new function of Rab5a as a control protein for directing concentration-dependent trafficking of the NK1R into different intracellular compartments and obtained evidence that Rab4a and Rab11a contribute to G-protein-coupled receptor recycling from early endosomes.
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U2 - 10.1074/jbc.M402479200
DO - 10.1074/jbc.M402479200
M3 - Article
C2 - 15128739
AN - SCOPUS:3142666167
SN - 0021-9258
VL - 279
SP - 30670
EP - 30679
JO - Journal of Biological Chemistry
JF - Journal of Biological Chemistry
IS - 29
ER -