演題詳細
Symposium
Sculpting the neuronal intracellular environment: from single molecule behavior to local signal integration
Sculpting the neuronal intracellular environment: from single molecule behavior to local signal integration
開催日 | 2014/9/12 |
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時間 | 9:00 - 11:00 |
会場 | Room B(501) |
Chairperson(s) | 合田 裕紀子 / Yukiko Goda (理化学研究所 脳科学総合研究センター シナプス可塑性・回路制御研究チーム / RIKEN, Brain Science Institute, Japan) 瀬藤 光利 / Mitsutoshi Setou (浜松医科大学 解剖学講座 細胞生物学分野 / Department of Cell Biology and Anatomy Hamamatsu University School of Medicine, Japan) |
シナプスとイニシャルセグメント領域における細胞膜分子の異常な拡散挙動:1分子追跡による解明
Abnormal dynamics of plasma membrane molecules in synapses and initial segments as revealed by single-molecule tracking
- S2-B-1-2
- 楠見 明弘 / Akihiro Kusumi:1
- 1:京都大学 物質-細胞統合システム拠点 再生医科学研究所 / Institute for Integrated Cell-Material Sciences and Institute for Frontier Medical Sciences, Kyoto Univ., Japan
Methods for imaging and tracking single molecules conjugated with fluorescent probes, called single
(fluorescent-)molecule tracking (SMT), are now providing researchers with the unprecedented ability to directly observe single-molecule behaviors in living cells at a spatial precisions of ~20 nm and time resolutions up to ~0.033 ms (enhanced by a factor of 100 from normal video rate). In this talk, I will address the following two points based on the findings made by advanced SMT methods.
Recently, various SMT results have advanced the concept of synapses as dynamic entities, in which their constituent molecules are continually re-organized. We have obtained evidence showing that even non-synaptic molecules almost freely enter the post-synaptic regions of the plasma membrane (PM), diffuse there, and exit from there. This result suggests that the PM post-synapse domain largely consists of the fluid membrane, like that in the bulk domain, perhaps dotted by small protein complexes (islands) consisting of synapse-specific transmembrane proteins and cytoskeletal proteins, termed by us the "archipelago architecture" in the context of focal-adhesion research. In the focal adhesion zone, the fluid membrane region is coated by the actin-based membrane skeleton (MSK), which is very similar to that found in the bulk PM.
In the PM initial segment region, the actin-based MSK, together with various transmembrane proteins anchored to it, was found to form a molecule-selective filter (diffusion barrier). How the selectivity is induced is under investigation.