[IP3 receptor, a Ca2+ oscilator--role of IP3 receptor in development and neural plasticity].
IP3 is an important second messenger to release Ca2+ from internal store. IP3receptor (IP3R) works as an IP3 induced Ca2+ release channel and requires IP3 and Ca2+ as coagoinist. We found IP3R is involved in fertilization, meiosis and mitosis by using a specific antibody. We further found that IICR is essential for determination of dorsoventral axis formation. Neuronal type 1 IP3R-deficient mice generated by a gene-targeting technique exhibit a significant reduction of birth rate and abnormal behavior (ataxia and seizure). Long-term depression of the cerebellum was blocked in the type 1 IP3R-deficient mice. Long-term potentiation (LTP) of CA1 hippocampus was enhanced but depotentiation and LTP suppression was reduced in IP3R1-deficient mice. These evidences suggest that IICR is involved in neuronal plasticity. The coupling mechanism between ER Ca2+ stores and plasma membrane store-operated channels is crucial to Ca2+ signaling. Recently we found that IP3R interacts with the TRP3 Ca2+ channel on the plasma membrane and functional coupling of IP3R to TRP3 channel is important for store operated Ca2+ entry. Recently we found that IP3R is involved in determination of polarity and input specificity of activity-induced synaptic modification.
Mikoshiba
Katsuhiko
K
Lab. For Develop. Neurobiology, RIKEN Brain Science Institute, 2-1 Hirosawa, Wako 3510198, Saitama, Japan.
D000818:Animals; D001368:Axis, Cervical Vertebra / Q000196:embryology; D002118:Calcium / Q000378:metabolism*; D015220:Calcium Channels / Q000378:metabolism / Q000502:physiology*; D020013:Calcium Signaling / Q000502:physiology; D005306:Fertilization; D053496:Inositol 1,4,5-Trisphosphate Receptors; D051379:Mice; D009473:Neuronal Plasticity; D018160:Receptors, Cytoplasmic and Nuclear / Q000502:physiology*
D015220:Calcium Channels; D053496:Inositol 1,4,5-Trisphosphate Receptors; D018160:Receptors, Cytoplasmic and Nuclear; D002118:Calcium