Synapsin associates with cyclophilin B in an ATP- and cyclosporin A-dependent manner.
J Neurochem
; 93(6): 1401-11, 2005 Jun.
Article
em En
| MEDLINE
| ID: mdl-15935056
ABSTRACT
Immunophilins are ubiquitous enzymes responsible for proline isomerisation during protein synthesis and for the chaperoning of several membrane proteins. These activities can be blocked by the immunosuppressants cyclosporin A, FK506 and rapamycin. It has been shown that all three immunosuppressants have neurotrophic activity and can modulate neurotransmitter release, but the molecular basis of these effects is currently unknown. Here, we show that synapsin I, a synaptic vesicle-associated protein, can be purified from Torpedo cholinergic synaptosomes through its affinity to cyclophilin B, an immunophilin that is particularly abundant in brain. The interaction is direct and conserved in mammals, and shows a dissociation constant of about 0.5 microM in vitro. The binding between the two proteins can be disrupted by cyclosporin A and inhibited by physiological concentrations of ATP. Furthermore, cyclophilin B co-localizes with synapsin I in rat synaptic vesicle fractions and its levels in synaptic vesicle-containing fractions are decreased in synapsin knockout mice. These results suggest that immunophilins are involved in the complex protein networks operating at the presynaptic level and implicate the interaction between cyclophilin B and synapsins in presynaptic function.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Trifosfato de Adenosina
/
Sinapsinas
/
Ciclosporina
/
Terminações Pré-Sinápticas
/
Transmissão Sináptica
/
Peptidilprolil Isomerase
/
Ciclofilinas
/
Órgão Elétrico
Tipo de estudo:
Risk_factors_studies
Idioma:
En
Revista:
J Neurochem
Ano de publicação:
2005
Tipo de documento:
Article
País de afiliação:
França