Role of the synaptobrevin C terminus in fusion pore formation

TY - JOUR

T1 - Role of the synaptobrevin C terminus in fusion pore formation

AU - Ngatchou, Annita N

AU - Kisler, Kassandra

AU - Fang, Qinghua

AU - Walter, Alexander M

AU - Zhao, Ying

AU - Bruns, Dieter

AU - Sørensen, Jakob B

AU - Lindau, Manfred

PY - 2010/10/26

Y1 - 2010/10/26

N2 - Neurotransmitter release is mediated by the SNARE proteins synaptobrevin II (sybII, also known as VAMP2), syntaxin, and SNAP-25, generating a force transfer to the membranes and inducing fusion pore formation. However, the molecular mechanism by which this force leads to opening of a fusion pore remains elusive. Here we show that the ability of sybII to support exocytosis is inhibited by addition of one or two residues to the sybII C terminus depending on their energy of transfer from water to the membrane interface, following a Boltzmann distribution. These results suggest that following stimulation, the SNARE complex pulls the C terminus of sybII deeper into the vesicle membrane.Wepropose that this movement disrupts the vesicular membrane continuity leading to fusion pore formation. In contrast to current models, the experiments suggest that fusion pore formation begins with molecular rearrangements at the intravesicular membrane leaflet and not between the apposed cytoplasmic leaflets.

AB - Neurotransmitter release is mediated by the SNARE proteins synaptobrevin II (sybII, also known as VAMP2), syntaxin, and SNAP-25, generating a force transfer to the membranes and inducing fusion pore formation. However, the molecular mechanism by which this force leads to opening of a fusion pore remains elusive. Here we show that the ability of sybII to support exocytosis is inhibited by addition of one or two residues to the sybII C terminus depending on their energy of transfer from water to the membrane interface, following a Boltzmann distribution. These results suggest that following stimulation, the SNARE complex pulls the C terminus of sybII deeper into the vesicle membrane.Wepropose that this movement disrupts the vesicular membrane continuity leading to fusion pore formation. In contrast to current models, the experiments suggest that fusion pore formation begins with molecular rearrangements at the intravesicular membrane leaflet and not between the apposed cytoplasmic leaflets.

U2 - 10.1073/pnas.1006727107

DO - 10.1073/pnas.1006727107

M3 - Journal article

C2 - 20937897

SN - 0027-8424

JO - Proceedings of the National Academy of Sciences of the United States of America

JF - Proceedings of the National Academy of Sciences of the United States of America

ER -