PT  - JOURNAL ARTICLE
AU  - Wang, Chih-Tien
AU  - Grishanin, Ruslan
AU  - Earles, Cynthia A.
AU  - Chang, Payne Y.
AU  - Martin, Thomas F. J.
AU  - Chapman, Edwin R.
AU  - Jackson, Meyer B.
TI  - Synaptotagmin Modulation of Fusion Pore Kinetics in Regulated Exocytosis of Dense-Core Vesicles
AID  - 10.1126/science.1064002
DP  - 2001 Nov 02
TA  - Science
PG  - 1111--1115
VI  - 294
IP  - 5544
4099  - http://science.sciencemag.org/content/294/5544/1111.short
4100  - http://science.sciencemag.org/content/294/5544/1111.full
SO  - Science2001 Nov 02; 294
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.