PROPERTIES OF THE FUSION PORE THAT FORMS DURING EXOCYTOSIS OF A MAST-CELL SECRETORY VESICLE

被引:223
作者
SPRUCE, AE
BRECKENRIDGE, LJ
LEE, AK
ALMERS, W
机构
[1] Department of Physiology, Biophysics University of Washington, Seattle
关键词
D O I
10.1016/0896-6273(90)90192-I
中图分类号
Q189 [神经科学];
学科分类号
071006 ;
摘要
During exocytosis, secretory vesicles of mast cells generate current transient that marks the opening of the fusion pore, the first aqueous connection that forms between the vesicle lumen and the cell exterior. By recording and analyzing such current transients, we have tracked the conductance of the fusion pore over the first millisecond of its existence. The first opening of the pore occurs rapidly, generally within 100 μs at 23°C. The electric conductance of the pore is a few hundred picosiemens at first, but gradually increases over the subsequent milliseconds. Evidently the pore opens abruptly and then dilates. The initial conductance of the pore suggests a diameter comparable to that of a large ion channel. From an analysis of "capacitance flicker" we infer that a pore can increase its diameter severalfold and still close again completely. This suggests that several early events in membrane fusion are reversible. © 1990.
引用
收藏
页码:643 / 654
页数:12
相关论文
共 42 条
[1]   EXOCYTOSIS [J].
ALMERS, W .
ANNUAL REVIEW OF PHYSIOLOGY, 1990, 52 :607-624
[2]  
ALMERS W, 1988, MOL MECHANISMS MEMBR, P197
[3]   FINAL STEPS IN EXOCYTOSIS OBSERVED IN A CELL WITH GIANT SECRETORY GRANULES [J].
BRECKENRIDGE, LJ ;
ALMERS, W .
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA, 1987, 84 (07) :1945-1949
[4]   CURRENTS THROUGH THE FUSION PORE THAT FORMS DURING EXOCYTOSIS OF A SECRETORY VESICLE [J].
BRECKENRIDGE, LJ ;
ALMERS, W .
NATURE, 1987, 328 (6133) :814-817
[5]   EVOKED NEUROTRANSMITTER RELEASE - STATISTICAL EFFECTS OF NONUNIFORMITY AND NON-STATIONARITY [J].
BROWN, TH ;
PERKEL, DH ;
FELDMAN, MW .
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA, 1976, 73 (08) :2913-2917
[6]   SINGLE-CHANNEL EVENTS AND GATING BEHAVIOR OF THE CARDIAC GAP JUNCTION CHANNEL [J].
BURT, JM ;
SPRAY, DC .
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA, 1988, 85 (10) :3431-3434
[7]   HIGH MOLECULAR-WEIGHT POLYMERS BLOCK CORTICAL GRANULE EXOCYTOSIS IN SEA-URCHIN EGGS AT THE LEVEL OF GRANULE MATRIX DISASSEMBLY [J].
CHANDLER, DE ;
WHITAKER, M ;
ZIMMERBERG, J .
JOURNAL OF CELL BIOLOGY, 1989, 109 (03) :1269-1278
[8]   ARREST OF MEMBRANE-FUSION EVENTS IN MAST-CELLS BY QUICK-FREEZING [J].
CHANDLER, DE ;
HEUSER, JE .
JOURNAL OF CELL BIOLOGY, 1980, 86 (02) :666-674
[9]   FLUCTUATIONS IN THE MICROSECOND TIME RANGE OF THE CURRENT THROUGH SINGLE ACETYLCHOLINE-RECEPTOR ION CHANNELS [J].
COLQUHOUN, D ;
SAKMANN, B .
NATURE, 1981, 294 (5840) :464-466
[10]  
DETOLEDO GA, 1988, CELL PHYSL BLOOD, P333