Noncoordinate regulation of ENaC: paradigm lost?
Noncoordinate regulation of ENaC: paradigm lost?
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ENaC 的非协调调节：范式丢失？
DOI：
10.1152/ajprenal.00088.2003
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发表时间：
2003
期刊：
影响因子：
--
通讯作者：
Johnson,JohnP
中科院分区：
文献类型：
--
作者：
Weisz,OraA;Johnson,JohnP
上皮钠通道（ENaC）由三个同源亚基α、β和γ组成。从异源系统中的所有研究中推断的基本寡聚化过程是三个亚基优先组装成单个寡聚体形式。然而，也有相当多的证据表明，在某些情况下可以形成仅由α-、αβ-或αγ-亚基组成的通道，并且在异源系统中表达的单个亚基可以运输到细胞膜。在表达内源性ENaC的细胞中，三个亚基通常以差异方式合成，其中一个或两个亚基组成型表达，而其他亚基由不同的生理刺激诱导，同时增加ENaC活性。这种现象，我们称之为非协调调节，已观察到全细胞和顶端膜ENaC亚基表达。还观察到其他几种异聚体膜蛋白在生物合成和膜定位后具有不同的周转率或单个亚基的运输率。在这里，我们研究的可能性，ENaC亚基的非协调调节可能是另一种机制，在阿森纳的生理反应，以不同的刺激。
The epithelial sodium channel (ENaC) is composed of the three homologous subunits α, β, and γ. The basic oligomerization process inferred from all studies in heterologous systems is preferential assembly of the three subunits into a single oligomeric form. However, there is also considerable evidence that channels composed of only α-, αβ-, or αγ-subunits can form under some circumstances and that individual subunits expressed in heterologous systems can traffic to the cell membrane. In cells that express endogenous ENaC, the three subunits are often synthesized in a differential fashion, with one or two subunits expressed constitutively while the other(s) are induced by different physiological stimuli in parallel with increased ENaC activity. This phenomenon, which we term noncoordinate regulation, has been observed for both whole cell and apical membrane ENaC subunit expression. Several other heteromeric membrane proteins have also been observed to have differential rates of either turnover or trafficking of individual subunits after biosynthesis and membrane localization. Here, we examine the possibility that noncoordinate regulation of ENaC subunits may represent another mechanism in the arsenal of physiological responses to diverse stimuli.