A functional channel is necessary for growth suppression by Cx37
A functional channel is necessary for growth suppression by Cx37
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DOI：
10.1242/jcs.081695
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发表时间：
2011-07-15
影响因子：
4
通讯作者：
Burt, Janis M.
中科院分区：
文献类型：
--
作者：
Good, Miranda E.;Nelson, Tasha K.;Burt, Janis M.
连接蛋白37（Cx 37）通过未知的机制深刻地抑制大鼠胰岛素瘤（Rin）细胞的增殖。为了确定功能性孔结构域是否是Cx 37介导的生长抑制所必需的，我们引入了将苏氨酸154转化为丙氨酸的突变（T154 A）。与其他同源位点突变的连接蛋白一样，Cx 37-T154 A定位于并置膜，但未能形成功能通道，并对共表达的野生型Cx 37或Cx43产生显性负效应。与野生型蛋白不同，Cx 37-T154 A不抑制Rin细胞的增殖，并且在血清剥夺的情况下不导致细胞周期停滞。此外，通过细胞周期的进展不受Cx 37-T154 A表达的影响。这些结果表明，能够形成功能性通道的成孔结构域对于Cx 37的抗增殖、细胞周期阻滞和血清敏感性作用是必不可少的，此外，正常定位的C-末端结构域对于Cx 37的这些作用是不够的。
Connexin 37 (Cx37) profoundly suppresses the proliferation of rat insulinoma (Rin) cells by unknown mechanisms. To determine whether a functional pore domain is necessary for Cx37-mediated growth suppression, we introduced a mutation that converted threonine 154 into alanine (T154A). Like other connexins mutated at the homologous site, Cx37-T154A localized to appositional membrane but failed to form functional channels and exerted a dominant-negative effect on coexpressed wild-type Cx37 or Cx43. Unlike the wild-type protein, Cx37-T154A did not suppress the proliferation of Rin cells and did not, with serum deprivation, result in cell cycle arrest. Furthermore, progression through the cell cycle was unaffected by expression of Cx37-T154A. These results indicate that a pore-forming domain that is able to form functional channels is essential for the anti-proliferative, cell-cycle arrest and serum-sensitivity effects of Cx37, and furthermore that the normally localized C-terminal domain is not sufficient for these effects of Cx37.