Recoverin regulates light-dependent phosphodiesterase activity in retinal rods.
J Gen Physiol
; 123(6): 729-41, 2004 Jun.
Article
em En
| MEDLINE
| ID: mdl-15173221
ABSTRACT
The Ca2+-binding protein recoverin may regulate visual transduction in retinal rods and cones, but its functional role and mechanism of action remain controversial. We compared the photoresponses of rods from control mice and from mice in which the recoverin gene was knocked out. Our analysis indicates that Ca2+-recoverin prolongs the dark-adapted flash response and increases the rod's sensitivity to dim steady light. Knockout rods had faster Ca2+ dynamics, indicating that recoverin is a significant Ca2+ buffer in the outer segment, but incorporation of exogenous buffer did not restore wild-type behavior. We infer that Ca2+-recoverin potentiates light-triggered phosphodiesterase activity, probably by effectively prolonging the catalytic activity of photoexcited rhodopsin.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Proteínas de Ligação ao Cálcio
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Células Fotorreceptoras Retinianas Bastonetes
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Diester Fosfórico Hidrolases
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Sinalização do Cálcio
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Proteínas do Olho
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Luz
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Lipoproteínas
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Potenciais da Membrana
Limite:
Animals
Idioma:
En
Revista:
J Gen Physiol
Ano de publicação:
2004
Tipo de documento:
Article
País de afiliação:
Estados Unidos