山形 要人 東京都神経科学総合研究所, 分子神経生物学部門生物学部門, 副参事 (20263262)
YONEDA Yoshihiro Osaka Univ.Med.Sch.Anatomy, Professor, 医学部, 教授 (80191667)
FUJIMOTO Toyoshi GUNMA Univ.Med.Sch.Anatomy, Professor, 医学部, 教授 (50115929)
SENBA Emika Wakayama Prefectural Med.Sch.Anatomy, Professor, 医学部, 教授 (00135691)
SAITO Naoaki Kobe Univ.Biosignal Center, Pharm.Professor, バイオシグナル研究センター, 教授 (60178499)
ABE Hiroshi Tokai Univ.Med.Sch., Morphology, Professor, 医学部, 教授 (40151104)
柴田 洋三郎 九州大学, 医学部, 教授 (90037482)
石川 春律 群馬大学, 医学部, 教授 (90010058)
|Budget Amount *help
¥4,300,000 (Direct Cost : ¥4,300,000)
Fiscal Year 1996 : ¥4,300,000 (Direct Cost : ¥4,300,000)
The expression and regulation of signal-related molecules were analyzed at levels of genes and proteins in cells in-vitro and in-vivo with regard to their relation to the plasma wembrane, cytoskeletons, cytoplasmic matrix and nucleus. Targeted molecules and structural elements analyzed in this study were the membranous caveolae, connexins. CD-38 molecule, membranous undercoats in the plasma membrane ; Ca/calmodulin-dependent protein kinase IV (CaMK-IV), diacylglycerol kinase (DGK), protein kinase C (PKC) and vesicle-associated small G-proteinin in the cytoplasmic matrix ; nuclear import factors and immediate early genes in the nucleus.
The sequestration of GPI-anchored proteins, glycosphingolipids and sphingomyelin in the caveolae were shown to be results of cross-linking, although the localization of caveolin there were constitutive. CD-38, a cell surface-antigen having an activity of cyclic ADP-ribose synthase, was localized in glia, but not neurons, suggesting a new way of functional
exertion of cyclic ADP-ribose synthase in the neuroanl signal transduction. The localization of dystrophin in the membranous undercoat of muscle cells were clarified in details and its topographical relation to cytoskeletons and exoplasmic surface structures were shown in ultrastructure. The heterogeneity in molecular structure and localization was clarified for DGK,CaMK-IV and PKC,and the nuclear localization of DGK-IV and CaMK-IV was revealed. The identification of novel cytoplasmic components and their importance in the nuclear protein-import were clarified in cultured cells. In the nucleus in vivo, changes in the expression of several immediate early genes occurred after various exogenous stimuli such as pain. A novel immediately early gene was identified from the hippocampus, implicating its functional involvement in synaptic plasticity. A small G-protein, rab 12 is shown to be involved in the secretory vesicle transport in atrial muscle cells. In conclusion, all these findings are of extreme importance in understanding the signal transduction mechanism in relation to cellular ultrastructure.
核移行の分子機構については,核膜孔ターゲッチング複合体を同定し,これが複数の相同分子から構成されること,さらに細胞外刺激で核移行するタンパクの一つ(Statl)は移行にリン酸化を受けることを明らかにした.また,外的刺激によるシグナルカスケード進行の結果として惹起される細胞反応として,既知のimmediate early genes(IEG)である細胞性ガン遺伝子(c-fos,c-jun,NGFI-A等)の多様な発現変動の詳細な解析,および新たなIGE(Arc:actively and developmentally regulated gene associated with cytoskeleton)を脳海馬で見出してそのシナプス可塑性への関与の可能性を検討した.そのうえ,発現タンパクの膜への移行に重要な細胞内小胞輸送機構の理解のためにそれに関与するsmall G-protein結合タンパクのうちrab12に注目して,心房筋細胞ANP顆粒の分泌にこのタンパクが関与することを免疫脂肪化学的に明らかにした. Less