RT Journal Article
SR Electronic
T1 Synaptotagmin Modulation of Fusion Pore Kinetics in Regulated Exocytosis of Dense-Core Vesicles
JF Science
JO Science
FD American Association for the Advancement of Science
SP 1111
OP 1115
DO 10.1126/science.1064002
VO 294
IS 5544
A1 Wang, Chih-Tien
A1 Grishanin, Ruslan
A1 Earles, Cynthia A.
A1 Chang, Payne Y.
A1 Martin, Thomas F. J.
A1 Chapman, Edwin R.
A1 Jackson, Meyer B.
YR 2001
UL http://science.sciencemag.org/content/294/5544/1111.abstract
AB In the exocytosis of neurotransmitter, fusion pore opening represents the first instant of fluid contact between the vesicle lumen and extracellular space. The existence of the fusion pore has been established by electrical measurements, but its molecular composition is unknown. The possibility that synaptotagmin regulates fusion pores was investigated with amperometry to monitor exocytosis of single dense-core vesicles. Overexpression of synaptotagmin I prolonged the time from fusion pore opening to dilation, whereas synaptotagmin IV shortened this time. Both synaptotagmin isoforms reduced norepinephrine flux through open fusion pores. Thus, synaptotagmin interacts with fusion pores, possibly by associating with a core complex of membrane proteins and/or lipid.