Dual role of calbindin-D28K in vesicular catecholamine release from mouse chromaffin cells.
J Neurochem
; 99(2): 628-40, 2006 Oct.
Article
em En
| MEDLINE
| ID: mdl-16824046
ABSTRACT
Calbindin-D(28K) is suggested to play a postsynaptic role in neurotransmission and in the regulation of the intracellular Ca(2+) concentration. However, it is still unclear whether calbindin-D(28K) has a role in the regulation of exocytosis, either as Ca(2+) buffer or as Ca(2+) sensor. Amperometric recordings of catecholamine exocytosis from wild-type and calbindin-D(28K) knockout mouse chromaffin cells reveal a strong reduction in the number of released vesicles, as well as in the amount of neurotransmitter released per fusion event in knockout cells. However, Ca(2+) current recordings and Ca(2+) imaging experiments, including video-rate confocal laser scanning microscopy, revealed that the intracellular Ca(2+) dynamics are remarkably similar in wild-type and knockout cells. The combined results demonstrate that calbindin-D(28K) plays an important and dual role in exocytosis, affecting both release frequency and quantal size, apparently without strong effects on intracellular Ca(2+) dynamics. Consequently, the possibility that calbindin-D(28K) functions not only as a Ca(2+) buffer but also as a modulator of vesicular catecholamine release is discussed.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Proteína G de Ligação ao Cálcio S100
/
Catecolaminas
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Medula Suprarrenal
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Células Cromafins
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Sinalização do Cálcio
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Vesículas Citoplasmáticas
Limite:
Animals
Idioma:
En
Revista:
J Neurochem
Ano de publicação:
2006
Tipo de documento:
Article
País de afiliação:
Holanda