| Induction of Connexin-hemichannel Opening
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Author:
Date:
2014-09-05
[Abstract] Connexins (Cxs) are integral membrane proteins of vertebrates that associate to form hexameric transmembrane channels, named hemichannels. Twenty-one Cx types have been described, which are named according to their molecular weight. Cxs are expressed in many cell types, e.g. epithelial cells, astrocytes and immune cells. Hemichannels allow the passage of molecules of up to 1-2 kDa along the concentration gradient. When surface-exposed, hemichannels mediate the exchange of molecules between the cytosol and the extracellular space. Hemichannels are closed by default, but several cues inducing their opening have been described, e.g. a drop in the extracellular Ca2+ concentration (Evans et al., 2006) or infection with enteric pathogens (Puhar et al. ...
[摘要] 连接蛋白（Cxs）是脊椎动物的内在膜蛋白，其结合形成六聚体跨膜通道，称为半通道。已经描述了21种Cx类型，其根据它们的分子量命名。 Cxs在许多细胞类型中表达，例如上皮细胞，星形胶质细胞和免疫细胞。半通道允许高达1-2kDa的分子沿浓度梯度通过。当表面暴露时，半通道介导细胞溶质和细胞外空间之间的分子交换。半通道被默认关闭，但是已经描述了诱导其开放的几个线索，例如，细胞外Ca 2+浓度的下降（Evans等人， 2006）;或用肠道病原体感染（Puhar et al。，2013; Tran Van Nhieu等人，2003）。该方案与上皮细胞，特别是与极化和非极化肠上皮TC7细胞和用Cx26或Cx43稳定转染的Hela细胞（Paemeleire等人，2000）一起使用。然而，它可能可用于其他Cx表达细胞类型。是否半通道是开放的可以通过电生理学或通过测量半通道可渗透分子（例如，ATP）在细胞外介质中的释放或半通道可渗透的质膜不渗透分子的摄取来确定[例如，荧光染料溴化乙锭 - 参见相关协议"通过Connexin Hemichannels进行染料吸收实验"（Puhar和Sansonetti，2014 ）]。
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| Dye-uptake Experiment through Connexin Hemichannels
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Author:
Date:
2014-09-05
[Abstract] Connexins (Cxs) are integral membrane proteins of vertebrates that associate to form hexameric transmembrane channels, named hemichannels. Twenty-one Cx types have been described, which are named according to their molecular weight. Cxs are expressed in many cell types, e.g. epithelial cells, astrocytes and immune cells. Hemichannels allow the passage of molecules of up to 1-2 kDa along the concentration gradient. When surface-exposed, hemichannels mediate the exchange of molecules between the cytosol and the extracellular space. Hemichannels are closed by default, but several cues inducing their opening have been described, e.g. a drop in the extracellular Ca2+ concentration (Evans et al., 2006) or infection with enteric pathogens (Puhar et al. ...
[摘要] 连接蛋白（Cxs）是脊椎动物的内在膜蛋白，其结合形成六聚体跨膜通道，称为半通道。已经描述了21种Cx类型，其根据它们的分子量命名。 Cxs在许多细胞类型中表达，例如上皮细胞，星形胶质细胞和免疫细胞。半通道允许高达1-2kDa的分子沿浓度梯度通过。当表面暴露时，半通道介导细胞溶质和细胞外空间之间的分子交换。半通道被默认关闭，但是已经描述了诱导其开放的几个线索，例如，细胞外Ca 2+浓度的下降（Evans等人， 2006）;或用肠道病原体感染（Puhar et al。，2013; Tran Van Nhieu等人，2003）。半通道开放可以通过电生理学，通过定量半通道可渗透分子到胞外培养基中的释放或通过量化半通道可透性，质膜不渗透分子的吸收来测量。由于分子的摄取程度与其浓度，暴露时间，温度（这些参数是受控的）成比例的，并且重要的是与细胞表面上的活性半通道的数目成比例，摄取测定常规用于评估半通道开放。用于摄取荧光染料溴化乙锭的方案与用Cx26或Cx43稳定转染的Hela细胞一起使用（Paemeleire等人，2000）。然而，它可能可用于其他Cx表达细胞类型。
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