Artículos de revistas
The immediately releasable pool of mouse chromaffin cell vesicles is coupled to P/Q-type calcium channels via the synaptic protein interaction site
Fecha
2013-01Registro en:
Alvarez, Yanina Daniela; Belingheri, Ana Verónica; Perez Bay, Andrés Ezequiel; Javis, Scott E.; Tedford, H. William; et al.;The immediately releasable pool of mouse chromaffin cell vesicles is coupled to P/Q-type calcium channels via the synaptic protein interaction site; Public Library Science; Plos One; 8; 1; 1-2013; e054846
1932-6203
Autor
Alvarez, Yanina Daniela
Belingheri, Ana Verónica
Perez Bay, Andrés Ezequiel
Javis, Scott E.
Tedford, H. William
Zamponi, Gerald
Marengo, Fernando Diego
Resumen
It is generally accepted that the immediately releasable pool is a group of readily releasable vesicles that are closely associated with voltage dependent Ca(2+) channels. We have previously shown that exocytosis of this pool is specifically coupled to P/Q Ca(2+) current. Accordingly, in the present work we found that the Ca(2+) current flowing through P/Q-type Ca(2+) channels is 8 times more effective at inducing exocytosis in response to short stimuli than the current carried by L-type channels. To investigate the mechanism that underlies the coupling between the immediately releasable pool and P/Q-type channels we transiently expressed in mouse chromaffin cells peptides corresponding to the synaptic protein interaction site of Cav2.2 to competitively uncouple P/Q-type channels from the secretory vesicle release complex. This treatment reduced the efficiency of Ca(2+) current to induce exocytosis to similar values as direct inhibition of P/Q-type channels via ω-agatoxin-IVA. In addition, the same treatment markedly reduced immediately releasable pool exocytosis, but did not affect the exocytosis provoked by sustained electric or high K(+) stimulation. Together, our results indicate that the synaptic protein interaction site is a crucial factor for the establishment of the functional coupling between immediately releasable pool vesicles and P/Q-type Ca(2+) channels.