FXYD3 (Mat-8), a new regulator of Na,K-ATPase
FXYD3 (Mat-8), a new regulator of Na,K-ATPase
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DOI：
10.1091/mbc.e04-10-0878
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发表时间：
2005-05-01
影响因子：
3.3
通讯作者：
Geering, K
中科院分区：
文献类型：
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作者：
Crambert, G;Li, CM;Geering, K
FXYD蛋白家族的7个成员中有4个已被确定为Na，K-ATPase的特异性调节因子。在这项研究中，我们发现FXYD3，也被称为Mat-8，能够与Na，K-ATPase结合并改变其转运特性。除了这一共享功能，FXYD3还表现出一些不同寻常的特点。首先，与其他被证明为I型膜蛋白的FXYD蛋白不同，FXYD3可能具有第二个跨膜型结构域，因为存在一个不可切割的信号肽。其次，FXYD3在非洲爪哇卵母细胞中表达时可与Na，K-ATPase和H，K-ATPase结合。然而，在原位(胃)，FXYD3只与Na，K-ATPase相关，因为它的表达仅限于H，K-ATPase缺失的粘液细胞。FXYD3在非洲爪哇卵母细胞中共表达，依赖于信号肽的存在，调节X，K-ATPaseβ亚基的糖基化过程。FXYD3降低了Na，K-ATPase对Na+和K+的表观亲和力。
Four of the seven members of the FXYD protein family have been identified as specific regulators of Na,K-ATPase. In this study, we show that FXYD3, also known as Mat-8, is able to associate with and to modify the transport properties of Na,K-ATPase. In addition to this shared function, FXYD3 displays some uncommon characteristics. First, in contrast to other FXYD proteins, which were shown to be type I membrane proteins, FXYD3 may have a second transmembrane-like domain because of the presence of a noncleavable signal peptide. Second, FXYD3 can associate with Na,K- as well as H,K-ATPases when expressed in Xenopus oocytes. However, in situ (stomach), FXYD3 is associated only with Na,K-ATPase because its expression is restricted to mucous cells in which H,K-ATPase is absent. Coexpressed in Xenopus oocytes, FXYD3 modulates the glycosylation processing of the beta subunit of X,K-ATPase dependent on the presence of the signal peptide. Finally, FXYD3 decreases both the apparent affinity for Na+ and K+ of Na,K-ATPase.