Author | dc.contributor.author | Castillo, Karen | |
Author | dc.contributor.author | Delgado Arriagada, Ricardo | es_CL |
Author | dc.contributor.author | Bacigalupo Vicuña, Juan | es_CL |
Admission date | dc.date.accessioned | 2011-03-31T12:13:34Z | |
Available date | dc.date.available | 2011-03-31T12:13:34Z | |
Publication date | dc.date.issued | 2007-09-03 | |
Cita de ítem | dc.identifier.citation | EUROPEAN JOURNAL OF NEUROSCIENCE, Volume: 26, Issue: 9, Pages: 2524-2531, 2007 | en_US |
Identifier | dc.identifier.issn | 0953-816X | |
Identifier | dc.identifier.uri | https://repositorio.uchile.cl/handle/2250/119123 | |
Abstract | dc.description.abstract | Olfactory sensory neurons respond to odorants increasing Ca2+ concentrations in their chemosensory cilia. Calcium enters the cilia
through cAMP-gated channels, activating Ca2+-dependent chloride or potassium channels. Calcium also has a fundamental role in
odour adaptation, regulating cAMP turnover rate and the affinity of the cyclic nucleotide-gated channels for cAMP. It has been shown
that a Na+ ⁄ Ca2+ exchanger (NCX) extrudes Ca2+ from the cilia. Here we confirm previous evidence that olfactory cilia also express
plasma membrane Ca2+-ATPase (PMCA), and show the first evidence supporting a role in Ca2+ removal. Both transporters were
detected by immunoblot of purified olfactory cilia membranes. The pump was also revealed by immunocytochemistry and
immunohistochemistry. Inside-out cilia membrane vesicles transported Ca2+ in an ATP-dependent fashion. PMCA activity was
potentiated by luminal Ca2+ (K0.5 ¼ 670 nm) and enhanced by calmodulin (CaM; K0.5 ¼ 31 nm). Both carboxyeosin (CE) and
calmidazolium reduced Ca2+ transport, as expected for a CaM-modulated PMCA. The relaxation time constant (s) of the Ca2+-
dependent Cl– current (272 ± 78 ms), indicative of luminal Ca2+ decline, was increased by CE (2181 ± 437 ms), by omitting ATP
(666 ± 49 ms) and by raising pH (725 ± 65 ms), suggesting a role of the pump on Ca2+ clearance. Replacement of external Na+ by
Li+ had a similar effect (s ¼ 442 ± 8 ms), confirming the NCX involvement in Ca2+ extrusion. The evidence suggests that both Ca2+
transporters contribute to re-establish resting Ca2+ levels in the cilia following olfactory responses. | en_US |
Patrocinador | dc.description.sponsorship | This work was supported by FONDECYT 1050124,
Proyecto Anillo en Ciencia y Tecnologı´a ACT-45, Programa Bicentenario
CONICYT; MIDEPLAN ICM-P05-001-F (J.B.) and a CONICYT doctoral
fellowship (K.C.). J.B. holds a John S. Guggenheim Memorial Foundation
Fellowship. | en_US |
Lenguage | dc.language.iso | en | en_US |
Publisher | dc.publisher | BLACKWELL | en_US |
Keywords | dc.subject | Ca2+-dependent Cl– current | en_US |
Título | dc.title | Plasma membrane Ca2+-ATPase in the cilia of olfactory receptor neurons: Possible role in Ca2+ clearance | en_US |
Document type | dc.type | Artículo de revista | |