TY - JOUR
T1 - CaV1.3 as pacemaker channels in adrenal chromaffin cells
T2 - Specific role on exo- and endocytosis?
AU - Comunanza, Valentina
AU - Marcantoni, Andrea
AU - Vandael, David H.
AU - Mahapatra, Satyajit
AU - Gavello, Daniela
AU - Navarro-Tableros, Victor
AU - Carabelli, Valentina
AU - Carbone, Emilio
PY - 2010/11
Y1 - 2010/11
N2 - Voltage-gated L-type calcium channels (LTCCs) are expressed in adrenal chromaffin cells. Besides shaping the action potential (AP), LTCCs are involved in the excitation-secretion coupling controlling catecholamine release and in Ca2+-dependent vesicle retrieval. Of the two LTCCs expressed in chromaffin cells (CaV1.2 and CaV1.3), CaV1.3 possesses the prerequisites for pacemaking spontaneously firing cells: low-threshold, steep voltage-dependence of activation and slow inactivation. By using CaV1.3-/- KO mice and the AP-clamp it has been possible to resolve the time course of CaV1.3 pacemaker currents, which is similar to that regulating Substantia nigra dopaminergic neurons. In mouse chromaffin cells CaV1.3 is coupled to fast-inactivating BK channels within membrane nanodomains and controls AP repolarization. The ability to carry subthreshold Ca2+ currents and activate BK channels confers to CaV1.3 the unique feature of driving Ca2+ loading during long interspike intervals and, possibly, to control the Ca 2+-dependent exocytosis and endocytosis processes that regulate catecholamine secretion and vesicle recycling.
AB - Voltage-gated L-type calcium channels (LTCCs) are expressed in adrenal chromaffin cells. Besides shaping the action potential (AP), LTCCs are involved in the excitation-secretion coupling controlling catecholamine release and in Ca2+-dependent vesicle retrieval. Of the two LTCCs expressed in chromaffin cells (CaV1.2 and CaV1.3), CaV1.3 possesses the prerequisites for pacemaking spontaneously firing cells: low-threshold, steep voltage-dependence of activation and slow inactivation. By using CaV1.3-/- KO mice and the AP-clamp it has been possible to resolve the time course of CaV1.3 pacemaker currents, which is similar to that regulating Substantia nigra dopaminergic neurons. In mouse chromaffin cells CaV1.3 is coupled to fast-inactivating BK channels within membrane nanodomains and controls AP repolarization. The ability to carry subthreshold Ca2+ currents and activate BK channels confers to CaV1.3 the unique feature of driving Ca2+ loading during long interspike intervals and, possibly, to control the Ca 2+-dependent exocytosis and endocytosis processes that regulate catecholamine secretion and vesicle recycling.
KW - Action potential firing
KW - BK channels
KW - Ca-dependent secretion
KW - cAMP
KW - cGMP
KW - Hypoxia
KW - L-type calcium channels
KW - Pacemaking currents
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U2 - 10.4161/chan.4.6.12866
DO - 10.4161/chan.4.6.12866
M3 - Article
AN - SCOPUS:78650830600
VL - 4
JO - Channels
JF - Channels
SN - 1933-6950
IS - 6
ER -