Membrane topologies of neuronal SNARE folding intermediates.
Assembly of the SNARE complex is essential for neurotransmitter release at synapses. Target plasma membrane SNAREs (t-SNAREs) syntaxin 1A and SNAP-25 form the t-SNARE complex that serves as an intermediate toward final SNARE assembly with vesicle-associated SNARE (v-SNARE). Membrane topologies of syntaxin 1A and the t-SNARE complex were investigated using site-directed spin labeling EPR. EPR analysis revealed that the basic region at the membrane-water interface is unstructured but inserted into the membrane. Such membrane insertion leaves no gap between the t-SNARE core and the membrane. Yet the lack of structure could provide the flexibility necessary for the t-SNARE core. Further, the insertion of the basic interfacial region into the membrane may have profound implications for the mechanism of SNARE-induced membrane fusion.
Department of Biochemistry, Biophysics and Molecular Biology, Iowa State University, Ames, Iowa 50011, USA.
Chang Sup
CS
Kim
Dae-Hyuk
DH
Kweon
Yeon-Kyun
YK
Shin
D000595:Amino Acid Sequence; D000954:Antigens, Surface / Q000737:chemistry; D019281:Dimerization; D004578:Electron Spin Resonance Spectroscopy / Q000379:methods; D008561:Membrane Fusion / Q000502:physiology; D008565:Membrane Proteins / Q000737:chemistry* / Q000235:genetics / Q000502:physiology; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D009419:Nerve Tissue Proteins / Q000737:chemistry; D009474:Neurons / Q000737:chemistry*; D010446:Peptide Fragments / Q000737:chemistry / Q000502:physiology; D017510:Protein Folding; D050600:SNARE Proteins; D013113:Spin Labels; D050827:Syntaxin 1; D033921:Vesicular Transport Proteins
D000954:Antigens, Surface; D008565:Membrane Proteins; D009419:Nerve Tissue Proteins; D010446:Peptide Fragments; D050600:SNARE Proteins; D013113:Spin Labels; D050827:Syntaxin 1; D033921:Vesicular Transport Proteins