2004 Fiscal Year Final Research Report Summary
Functional studies for presynatic proteins which may control efficiency of synaptic transmission
| Project/Area Number |
14380369
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Neuroscience in general
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| Research Institution | Tokyo Medical University |
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Principal Investigator |
MOCHIDA Sumiko Tokyo Medical University, Professor, 医学部, 教授 (30096341)
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| Project Period (FY) |
2002 – 2004
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| Keywords | synaptic transmission / presynaptic terminal proteins / Ca^<2+> / Calmodulin / Ca^<2+> channels / Ca^<2+>-binding protein / GTP-binding protein / Motor protein / sympathetic neurons in culture |
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| Research Abstract |
Neurotransmitter release is triggered by Ca^<2+> entered into presynaptic nerve terminals through voltage-dependent Ca^<2+> channels activated by an action potential. Recently, various proteins were found in presynaptic terminals. For example, SNARE proteins which form a core complex and involved in synaptic vesicle exocytosis, synaptic vesicle proteins or synaptic vesicle associated with Ca^<2+>sensor proteins, active zone cytomatrix proteins that also form a complex and motor proteins that may mobilize synaptic vesicles, and Ca^<2+> channel interacting proteins which may control Ca^<2+> channel activity.
To examine possible roles of these proteins in regulation of synaptic transmission efficiency, we employed synapses formed between rat superior cervical ganglion neurons in long-term culture. We introduced exogenous synthesized peptides or, protein, or transfected cDNAs of a presynaptic protein and monitored changes in synaptic transmissionby recording excitatory postsynaptic potentials generated by presynaptic action potentials. We revealed a mechanism of regulation of SNARE complex formation by binding of Ca^<2+>/Calmodulin to syntaxin IA^<1)>, functional differences between three types of Ca^<2+> channels expressed in the brain^<2)> a possible role of cytomatrix proteins at the active zone^<3)>, regulation of exocytosis by SV2 binding to a Ca^<2+> sensor synaptotagmin^<4)>, regulation of exocytosis by G-protein βγ subunit binding to N-type Ca^<2+> channel^<5)>, regulation of synaptic vesicle trafficking by myosin IIB but not by IIA, Va or Vb (preparing for re-submission).
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