Inositol 1,4,5-trisphosphate-gated calcium transport through plasma membranes in nerve terminals.
We developed new biochemical approaches to demonstrate the presence of inositol 1,4,5-triphosphate (InsP3)-gated calcium channels in presynaptic plasma membranes (SPM) and their involvement in the presynaptic receptor-mediated Ca2+ influx into nerve terminals. In perfusion experiments using SPM vesicles preloaded with 45Ca2+, InsP3 elicited the release of 45CA2+ into perfusates in a saturable manner. The InsP3- evoked 45Ca2+ release from resealed SPM vesicles was more potent than that from resealed vesicles using any other subcellular fractions. Here we also report the involvement of InsP3-gated mechanisms in the presynaptic receptor-mediated Ca2+ influx into synaptosomes (nerve terminals) by use of such resealed vesicles reconstituted with purified Gi1.
Ueda
H
H
Department of Pharmacology, Yokohama City University School of Medicine, Japan.
Tamura
S
S
Fukushima
N
N
Katada
T
T
Ui
M
M
Satoh
M
M
D000255:Adenosine Triphosphate / Q000502:physiology; D000818:Animals; D001692:Biological Transport / Q000187:drug effects; D000001:Calcimycin / Q000494:pharmacology; D002118:Calcium / Q000378:metabolism*; D015220:Calcium Channels / Q000187:drug effects*; D002462:Cell Membrane / Q000378:metabolism; D004723:Endorphins / Q000494:pharmacology; D015544:Inositol 1,4,5-Trisphosphate / Q000502:physiology*; D015640:Ion Channel Gating / Q000187:drug effects; D007700:Kinetics; D008297:Male; D009411:Nerve Endings / Q000378:metabolism*; D017729:Presynaptic Terminals / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D013347:Subcellular Fractions / Q000378:metabolism; D013572:Synaptic Vesicles / Q000378:metabolism; D010566:Virulence Factors, Bordetella / Q000494:pharmacology
D015220:Calcium Channels; D004723:Endorphins; D010566:Virulence Factors, Bordetella; C019448:kyotorphin; D000001:Calcimycin; D015544:Inositol 1,4,5-Trisphosphate; D000255:Adenosine Triphosphate; D002118:Calcium