ATP dependence of the non-specific ion channel in Torpedo synaptic vesicles.
Synaptic vesicles of Torpedo electromotor neurons contain a high amount of ATP. The concentration of total ATP is around 120 mM, whereas the free [ATP] is about 5-6 mM. We examined the effect of intravesicular ATP on the non-specific ion channel in Torpedo-fused synaptic vesicles. It was found that this channel is closed when the ATP concentration is above 2 mM, but it is very frequently open at lower ATP concentrations. Unmasking this ion channel at a low ATP concentration may be significant for post-fusion control of transmitter release by the 'kiss and run' mechanism in normal conditions, while during metabolic stress it may underlie dissipation of important gradients across the vesicle membrane.
Ahdut-Hacohen
Ronit
R
Department of Physiology, The Hebrew University-Hadassah Medical School, Jerusalem, Israel.
Meiri
Halina
H
Rahamimoff
Rami
R
D000255:Adenosine Triphosphate / Q000378:metabolism* / Q000494:pharmacology; D000818:Animals; D015640:Ion Channel Gating / Q000187:drug effects / Q000502:physiology; D007473:Ion Channels / Q000187:drug effects / Q000502:physiology*; D008564:Membrane Potentials / Q000187:drug effects / Q000502:physiology / Q000528:radiation effects; D009046:Motor Neurons / Q000166:cytology; D018408:Patch-Clamp Techniques / Q000379:methods; D011336:Probability; D013572:Synaptic Vesicles / Q000187:drug effects / Q000502:physiology*; D013997:Time Factors; D014101:Torpedo / Q000033:anatomy & histology / Q000502:physiology*
D007473:Ion Channels; D000255:Adenosine Triphosphate