ミヤヤマ タカミツ   Takamitsu Miyayama
  宮山 貴光
   所属   医学部 医学科
   職種   助教
論文種別 原著
言語種別 英語
査読の有無 査読あり
表題 Roles of copper chaperone for superoxide dismutase 1 and metallothionein in copper homeostasis
掲載誌名 正式名:Metallomics
ISSNコード:1756591X/1756-5901
巻・号・頁 3(7),693-701頁
著者・共著者 MIYAYAMA Takamitsu†, ISHIZUKA Yudai, IIJIMA Tomomi, HIRAOKA Daisuke, OGRA Yasumitsu*
発行年月 2011/07
概要 Copper chaperone for SOD1 (CCS) specifically delivers copper (Cu) to copper, zinc superoxide dismutase (SOD1) in cytoplasm of mammalian cells. In the present study, small interfering RNA (siRNA) targeting CCS was introduced into metallothionein-knockout mouse fibroblasts (MT-KO cells) and their wild type cells (MT-WT cells) to reveal the interactive role of CCS with other Cu-regulating proteins, in particular, MT. CCS knockdown significantly decreased Ctr1, a Cu influx transporter, mRNA expression. On the other hand, Atp7a, a Cu efflux transporter, mRNA expression was increased 3.0 and 2.5 times higher than those of the control in MT-WT and MT-KO cells. These responses of Cu-regulating genes to the CCS knockdown reflected the presence of excess Cu in the cells. To evaluate the Atp7a function in the Cu-replete cells, siRNA of Atp7a and the other Cu transporter, Atp7b were introduced into MT-WT and MT-KO cells. The Atp7a knockdown significantly increased the intracellular Cu concentration, whereas the Atp7b knockdown had no affect. Although two MT isoforms were induced by the CCS knockdown in MT-WT cells, the expression and activity of SOD1 were maintained in both MT-WT and MT-KO cells even when CCS protein expression was reduced to 0.30-0.35 of control. This suggests that the amount of CCS protein exceeds that required to supply Cu to SOD1 in the cells. Further, the CCS knockdown induces Cu accumulation in cells, however, the Cu accumulation is ameliorated by the MT induction, the decrease of Ctr1 expression and the increase of Atp7a expression to maintain Cu homeostasis.
DOI 10.1039/c1mt00016k
文献番号 21409224