Arrangements of proteins at reconstituted synaptic vesicle fusion sites depend on membrane separation.
FEBS Lett
; 594(21): 3450-3463, 2020 11.
Article
em En
| MEDLINE
| ID: mdl-32860428
ABSTRACT
Synaptic vesicle proteins, including N-ethylmaleimide-sensitive factor attachment protein receptors (SNAREs), Synaptotagmin-1 and Complexin, are responsible for controlling the synchronised fusion of synaptic vesicles with the presynaptic plasma membrane in response to elevated cytosolic calcium levels. A range of structures of SNAREs and their regulatory proteins have been elucidated, but the exact organisation of these proteins at synaptic junction membranes remains elusive. Here, we have used cryoelectron tomography to investigate the arrangement of synaptic proteins in an in vitro reconstituted fusion system. We found that the separation between vesicle and target membranes strongly correlates with the organisation of protein complexes at junctions. At larger membrane separations, protein complexes assume a 'clustered' distribution at the docking site, inducing a protrusion in the target membrane. As the membrane separation decreases, protein complexes become displaced radially outwards and assume a 'ring-like' arrangement. Our findings indicate that docked vesicles can possess a wide range of protein complex numbers and be heterogeneous in their protein arrangements.
Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Vesículas Sinápticas
/
Membrana Celular
/
Proteínas de Membrana
Idioma:
En
Revista:
FEBS Lett
Ano de publicação:
2020
Tipo de documento:
Article
País de afiliação:
Reino Unido
País de publicação:
ENGLAND
/
ESCOCIA
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GB
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GREAT BRITAIN
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INGLATERRA
/
REINO UNIDO
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SCOTLAND
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UK
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UNITED KINGDOM