The structure of Ca(2+) release units in arthropod body muscle indicates an indirect mechanism for excitation-contraction coupling.
Biophys J
; 83(5): 2742-53, 2002 Nov.
Article
em En
| MEDLINE
| ID: mdl-12414707
ABSTRACT
The relative disposition of ryanodine receptors (RyRs) and L-type Ca(2+) channels was examined in body muscles from three arthropods. In all muscles the disposition of ryanodine receptors in the junctional gap between apposed SR and T tubule elements is highly ordered. By contrast, the junctional membrane of the T tubule is occupied by distinctive large particles that are clustered within the small junctional domain, but show no order in their arrangement. We propose that the large particles of the junctional T tubules represent L-type Ca(2+) channels involved in excitation-contraction (e-c) coupling, based on their similarity in size and location with the L-type Ca(2+) channels or dihydropyridine receptors (DHPRs) of skeletal and cardiac muscle. The random arrangement of DHPRs in arthropod body muscles indicates that there is no close link between them and RyRs. This matches the architecture of vertebrate cardiac muscle and is in keeping with the similarity in e-c coupling mechanisms in cardiac and invertebrate striated muscles.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Cálcio
/
Músculos
Limite:
Animals
Idioma:
En
Revista:
Biophys J
Ano de publicação:
2002
Tipo de documento:
Article
País de afiliação:
Japão