Ca2+ release, which is necessary for muscle contraction, occurs at the j-SR (junctional domain of the sarcoplasmic reticulum). It requires the assembly of a large multiprotein complex containing the RyR (ryanodine receptor) and additional proteins, including triadin and calsequestrin. The signals which drive these proteins to the j-SR and how they assemble to form this multiprotein complex are poorly understood. To address aspects of these questions we studied the localization, dynamic properties and molecular interactions of triadin. We identified three regions, named TR1 (targeting region 1), TR2 and TR3, that contribute to the localization of triadin at the j-SR. FRAP experiments showed that triadin is stably associated with the j-SR and that this association is mediated by TR3. Protein pull-down experiments indicated that TR3 contains binding sites for calsequestrin-1 and that triadin clustering can be enhanced by binding to calsequestrin-1. These findings were confirmed by FRET experiments. Interestingly, the stable association of triadin to the j-SR was significantly decreased in myotubes from calsequestrin-1 knockout mice. Taken together, these results identify three regions in triadin that mediate targeting to the j-SR and reveal a role for calsequestrin-1 in promoting the stable association of triadin to the multiprotein complex associated with RyR.

Rossi, D., Bencini, C., Maritati, M., Benini, F., Lorenzini, S., Pierantozzi, E., et al. (2014). Distinct regions of triadin are required for targeting and retention at the junctional domain of the sarcoplasmic reticulum. BIOCHEMICAL JOURNAL, 458(2), 407-417 [10.1042/BJ20130719.].

Distinct regions of triadin are required for targeting and retention at the junctional domain of the sarcoplasmic reticulum

Rossi, D.;Bencini, C.;Maritati, M.;Lorenzini, S.;Pierantozzi, E.;Protasi, F.;Sorrentino, V.
2014-01-01

Abstract

Ca2+ release, which is necessary for muscle contraction, occurs at the j-SR (junctional domain of the sarcoplasmic reticulum). It requires the assembly of a large multiprotein complex containing the RyR (ryanodine receptor) and additional proteins, including triadin and calsequestrin. The signals which drive these proteins to the j-SR and how they assemble to form this multiprotein complex are poorly understood. To address aspects of these questions we studied the localization, dynamic properties and molecular interactions of triadin. We identified three regions, named TR1 (targeting region 1), TR2 and TR3, that contribute to the localization of triadin at the j-SR. FRAP experiments showed that triadin is stably associated with the j-SR and that this association is mediated by TR3. Protein pull-down experiments indicated that TR3 contains binding sites for calsequestrin-1 and that triadin clustering can be enhanced by binding to calsequestrin-1. These findings were confirmed by FRET experiments. Interestingly, the stable association of triadin to the j-SR was significantly decreased in myotubes from calsequestrin-1 knockout mice. Taken together, these results identify three regions in triadin that mediate targeting to the j-SR and reveal a role for calsequestrin-1 in promoting the stable association of triadin to the multiprotein complex associated with RyR.
Rossi, D., Bencini, C., Maritati, M., Benini, F., Lorenzini, S., Pierantozzi, E., et al. (2014). Distinct regions of triadin are required for targeting and retention at the junctional domain of the sarcoplasmic reticulum. BIOCHEMICAL JOURNAL, 458(2), 407-417 [10.1042/BJ20130719.].
File in questo prodotto:
File Dimensione Formato  
Rossi et al 2014 BJ.pdf

non disponibili

Tipologia: Post-print
Licenza: DRM non definito
Dimensione 1.57 MB
Formato Adobe PDF
1.57 MB Adobe PDF   Visualizza/Apri   Richiedi una copia

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11365/48968
 Attenzione

Attenzione! I dati visualizzati non sono stati sottoposti a validazione da parte dell'ateneo