Evidence for a role of caveolin-1 in neurokinin-1 receptor plasma-membrane localization, efficient signaling, and interaction with beta-arrestin 2.
Cell Tissue Res
; 330(2): 231-45, 2007 Nov.
Article
en En
| MEDLINE
| ID: mdl-17713785
ABSTRACT
This study was focused on the relationship between the plasma-membrane localization of neurokinin-1 receptor (NK1-R) and its endocytic and signaling properties. First, we employed electron paramagnetic resonance (EPR) to study the domain structure of HEK-293 cells and NK1-R microlocalization. EPR spectra and the GHOST condensation routine demonstrated that NK1-R was distributed in a well-ordered domain of HEK-293 cells possibly representing lipid raft/caveolae microdomains, whereas the impairment of caveolae changed the NK1-R plasma-membrane distribution. Internalization and second messenger assays combined with bioluminescence resonance energy transfer were employed subsequently to evaluate the functional importance of the NK1-R microlocalization in lipid raft/caveolae microdomains. The internalization pattern was delineated through the use of dominant-negative mutants (DNM) of caveolin-1 S80E (Cav1 S80E), dynamin-1 K44A (Dyn K44A), and beta-arrestin (beta-arr 319-418) and by means of cell lines that expressed various endogenous levels of beta-arrestins. NK1-R displayed rapid internalization that was substantially reduced by DNMs of dynamin-1 and beta-arrestin and even more profoundly in cells lacking both beta-arrestin1 and beta-arrestin2. These internalization data were highly suggestive of the predominant use of the clathrin-mediated pathway by NK1-R, even though NK1-R tended to reside constitutively in lipid raft/caveolae microdomains. Evidence was also obtained that the proper clustering of the receptor in these microdomains was important for effective agonist-induced NK1-R signaling and for its interaction with beta-arrestin2.
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Bases de datos:
MEDLINE
Asunto principal:
Transducción de Señal
/
Membrana Celular
/
Receptores de Neuroquinina-1
/
Arrestinas
/
Caveolas
/
Caveolina 1
Límite:
Animals
/
Humans
Idioma:
En
Revista:
Cell Tissue Res
Año:
2007
Tipo del documento:
Article
País de afiliación:
Eslovenia