Protein complex formation between Msx1 and Lhx2 homeoproteins is incompatible with DNA binding activity
Protein complex formation between Msx1 and Lhx2 homeoproteins is incompatible with DNA binding activity
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DOI：
10.1046/j.1432-0436.1998.6330151.x
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发表时间：
1998-07-01
期刊：
影响因子：
2.9
通讯作者：
Abate-Shen, C
中科院分区：
文献类型：
--
作者：
Bendall, AJ;Rincón-Limas, DE;Abate-Shen, C
Msx基因编码一个同源异型蛋白家族，通过蛋白质-蛋白质相互作用作为转录抑制因子发挥作用。在这里，我们表明，LHX 2，LIM型同源异型蛋白，是Msx 1在体外和细胞提取物中的蛋白质伴侣。Msx 1和Lhx 2之间的相互作用是通过两种蛋白质的含有同源结构域的区域介导的。有趣的是，LIM结构域，作为Lhx 2的其他合作伙伴的蛋白质相互作用结构域，不需要Msx 1-Lhx 2协会。我们表明，Msx 1和Lhx 2形成一个蛋白质复合物的DNA的情况下，和DNA结合的蛋白质单独可以发生在蛋白质复合物的形成为代价。Msx 1和Lhx 2的表达模式强调了这种蛋白质-蛋白质相互作用的重要性，Msx 1和Lhx 2在小鼠胚胎发生过程中部分重叠。Lhx 2作为Msx 1的蛋白质伴侣的描述表明，同源异型蛋白在体内的功能特异性是由它们与DNA及其蛋白质伴侣之间的平衡决定的。
Msx genes encode a family of homeoproteins that function as transcription repressors through protein-protein interactions. Here we show that Lhx2, a LIM-type homeoprotein, is a protein partner for Msx1 in vitro and in cellular extracts. The interaction between Msx1 and Lhx2 is mediated through the homeodomain-containing regions of both proteins. Interestingly, the LIM domains, which serve as protein interaction domains for other partners of Lhx2, are not required for the Msx1-Lhx2 association. We show that Msx1 and Lhx2 form a protein complex in the absence of DNA, and that DNA binding by either protein alone can occur at the expense of protein complex formation. The significance of this protein-protein interaction is underscored by the expression patterns of Msx1 and Lhx2, which are partially overlapping during murine embryogenesis. The description of Lhx2 as a protein partner for Msx1 suggests that the functional specificity of homeoproteins in vivo is determined by a balance between their association with DNA and their protein partners.