Structural Mechanism of Soluble N-ethylmaleimide-Sensitive Factor Attachment Protein Receptor Complex Assembly in Lipid Bilayers Revealed by Solid-State NMR.
J Am Chem Soc
; 145(19): 10641-10650, 2023 05 17.
Article
em En
| MEDLINE
| ID: mdl-37158674
ABSTRACT
Synaptic vesicle fusion is mediated by soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE) proteins, including synaptobrevin-2 (Syb-2), syntaxin-1 (Syx-1), and SNAP-25. However, it remains controversial whether the formation of thoroughly contacted α-helical bundle from the SNARE motifs to the end of the transmembrane domains (TMDs) is necessary for SNARE-mediated membrane fusion. In this study, we characterized the conformation of Syb-2 in different assembly states using a combination of dipolar- and scalar-based solid-state NMR experiments in lipid bilayers. Our spectral analysis revealed a highly dynamic nature of the Syb-2 TMD with considerable α-helical contents. Chemical shift perturbation and mutational analysis indicated that the coupling between Syb-2 and Syx-1 TMDs mediated by residue Gly-100 of Syb-2 together with high mobility of the C-terminal segment of Syb-2 TMD are required for inner membrane merger. Our results provide new insights into the role of the Syb-2 TMD in driving membrane fusion, which improves the current understanding of the structural mechanism of SNARE complex assembly. This study highlights the significance of membrane environments in elucidating the mechanism of membrane proteins.
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Proteínas SNARE
/
Bicamadas Lipídicas
Idioma:
En
Ano de publicação:
2023
Tipo de documento:
Article