Neuronal calcium sensor 1 and activity-dependent facilitation of P/Q-type calcium currents at presynaptic nerve terminals.
P/Q-type presynaptic calcium currents (IpCa) undergo activity-dependent facilitation during repetitive activation at the calyx of the Held synapse. We investigated whether neuronal calcium sensor 1 (NCS-1) may underlie this phenomenon. Direct loading of NCS-1 into the nerve terminal mimicked activity-dependent IpCa facilitation by accelerating the activation time of IpCa in a Ca2+-dependent manner. A presynaptically loaded carboxyl-terminal peptide of NCS-1 abolished IpCa facilitation. These results suggest that residual Ca2+ activates endogenous NCS-1, thereby facilitating IpCa. Because both P/Q-type Ca2+ channels and NCS-1 are widely expressed in mammalian nerve terminals, NCS-1 may contribute to the activity-dependent synaptic facilitation at many synapses.
Tsujimoto
Tetsuhiro
T
Department of Neurophysiology, University of Tokyo Faculty of Medicine, Tokyo 113-0033, Japan. tujimoto-tky@umin.ac.jp
Jeromin
Andreas
A
Saitoh
Naoto
N
Roder
John C
JC
Takahashi
Tomoyuki
T
D000200:Action Potentials / Q000187:drug effects; D000595:Amino Acid Sequence; D000818:Animals; D001933:Brain Stem / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D002118:Calcium / Q000378:metabolism* / Q000494:pharmacology; D015220:Calcium Channels / Q000378:metabolism*; D002135:Calcium-Binding Proteins / Q000008:administration & dosage / Q000737:chemistry / Q000378:metabolism* / Q000494:pharmacology; D004553:Electric Conductivity; D066298:In Vitro Techniques; D015640:Ion Channel Gating / Q000187:drug effects; D008969:Molecular Sequence Data; D051580:Neuronal Calcium-Sensor Proteins; D009479:Neuropeptides / Q000008:administration & dosage / Q000737:chemistry / Q000378:metabolism* / Q000494:pharmacology; D017729:Presynaptic Terminals / Q000187:drug effects / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar
D015220:Calcium Channels; D002135:Calcium-Binding Proteins; D051580:Neuronal Calcium-Sensor Proteins; D009479:Neuropeptides; C101464:frequenin calcium sensor proteins; D002118:Calcium