Architecture of the synaptotagmin-SNARE machinery for neuronal exocytosis.
Synaptotagmin-1 and neuronal SNARE proteins have central roles in evoked synchronous neurotransmitter release; however, it is unknown how they cooperate to trigger synaptic vesicle fusion. Here we report atomic-resolution crystal structures of Ca(2+)- and Mg(2+)-bound complexes between synaptotagmin-1 and the neuronal SNARE complex, one of which was determined with diffraction data from an X-ray free-electron laser, leading to an atomic-resolution structure with accurate rotamer assignments for many side chains. The structures reveal several interfaces, including a large, specific, Ca(2+)-independent and conserved interface. Tests of this interface by mutagenesis suggest that it is essential for Ca(2+)-triggered neurotransmitter release in mouse hippocampal neuronal synapses and for Ca(2+)-triggered vesicle fusion in a reconstituted system. We propose that this interface forms before Ca(2+) triggering, moves en bloc as Ca(2+) influx promotes the interactions between synaptotagmin-1 and the plasma membrane, and consequently remodels the membrane to promote fusion, possibly in conjunction with other interfaces.
Department of Molecular and Cellular Physiology, Howard Hughes Medical Institute, Stanford University, Stanford, California 94305, USA.|Departments of Neurology and Neurological Sciences, Photon Science, and Structural Biology, Stanford University, Stanford, California 94305, USA.
Qiangjun
Q
Zhou
Department of Molecular and Cellular Physiology, Howard Hughes Medical Institute, Stanford University, Stanford, California 94305, USA.|Departments of Neurology and Neurological Sciences, Photon Science, and Structural Biology, Stanford University, Stanford, California 94305, USA.
Ying
Y
Lai
Department of Molecular and Cellular Physiology, Howard Hughes Medical Institute, Stanford University, Stanford, California 94305, USA.
Taulant
T
Bacaj
Department of Molecular and Cellular Physiology, Howard Hughes Medical Institute, Stanford University, Stanford, California 94305, USA.|Departments of Neurology and Neurological Sciences, Photon Science, and Structural Biology, Stanford University, Stanford, California 94305, USA.
Minglei
M
Zhao
Department of Molecular and Cellular Physiology, Howard Hughes Medical Institute, Stanford University, Stanford, California 94305, USA.|Departments of Neurology and Neurological Sciences, Photon Science, and Structural Biology, Stanford University, Stanford, California 94305, USA.
Artem Y
AY
Lyubimov
Department of Molecular and Cellular Physiology, Howard Hughes Medical Institute, Stanford University, Stanford, California 94305, USA.|Departments of Neurology and Neurological Sciences, Photon Science, and Structural Biology, Stanford University, Stanford, California 94305, USA.
Monarin
M
Uervirojnangkoorn
Department of Molecular and Cellular Physiology, Howard Hughes Medical Institute, Stanford University, Stanford, California 94305, USA.|Departments of Neurology and Neurological Sciences, Photon Science, and Structural Biology, Stanford University, Stanford, California 94305, USA.
Oliver B
OB
Zeldin
Physical Biosciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA.
Aaron S
AS
Brewster
Physical Biosciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA.
Nicholas K
NK
Sauter
SLAC National Accelerator Laboratory, Stanford, California 94305, USA.
Aina E
AE
Cohen
SLAC National Accelerator Laboratory, Stanford, California 94305, USA.
S Michael
SM
Soltis
SLAC National Accelerator Laboratory, Stanford, California 94305, USA.
Roberto
R
Alonso-Mori
SLAC National Accelerator Laboratory, Stanford, California 94305, USA.
Matthieu
M
Chollet
SLAC National Accelerator Laboratory, Stanford, California 94305, USA.
Henrik T
HT
Lemke
Department of Molecular and Cellular Physiology, Howard Hughes Medical Institute, Stanford University, Stanford, California 94305, USA.|Departments of Neurology and Neurological Sciences, Photon Science, and Structural Biology, Stanford University, Stanford, California 94305, USA.
Richard A
RA
Pfuetzner
Department of Molecular and Cellular Physiology, Howard Hughes Medical Institute, Stanford University, Stanford, California 94305, USA.|Departments of Neurology and Neurological Sciences, Photon Science, and Structural Biology, Stanford University, Stanford, California 94305, USA.
Ucheor B
UB
Choi
Departments of Structural Biology, Molecular and Cellular Physiology, and Photon Science, Stanford University, Stanford, California 94305, USA.
William I
WI
Weis
Department of Molecular and Cellular Physiology, Howard Hughes Medical Institute, Stanford University, Stanford, California 94305, USA.|Departments of Neurology and Neurological Sciences, Photon Science, and Structural Biology, Stanford University, Stanford, California 94305, USA.
Jiajie
J
Diao
Department of Molecular and Cellular Physiology, Howard Hughes Medical Institute, Stanford University, Stanford, California 94305, USA.
Thomas C
TC
Südhof
Department of Molecular and Cellular Physiology, Howard Hughes Medical Institute, Stanford University, Stanford, California 94305, USA.|Departments of Neurology and Neurological Sciences, Photon Science, and Structural Biology, Stanford University, Stanford, California 94305, USA.
Axel T
AT
Brunger
D000818:Animals; D001665:Binding Sites / Q000235:genetics; D002118:Calcium / Q000737:chemistry / Q000378:metabolism; D002462:Cell Membrane / Q000378:metabolism; D018360:Crystallography, X-Ray; D004583:Electrons; D005089:Exocytosis; D006624:Hippocampus / Q000166:cytology; D007834:Lasers; D008274:Magnesium / Q000737:chemistry / Q000378:metabolism; D008561:Membrane Fusion; D051379:Mice; D008954:Models, Biological; D008958:Models, Molecular; D009154:Mutation / Q000235:genetics; D009474:Neurons / Q000737:chemistry / Q000166:cytology / Q000378:metabolism*; D050600:SNARE Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D009435:Synaptic Transmission; D013572:Synaptic Vesicles / Q000737:chemistry / Q000378:metabolism; D050857:Synaptotagmins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*
D050600:SNARE Proteins; D050857:Synaptotagmins; D008274:Magnesium; D002118:Calcium