Experimental identification of homodimerizing B-ZIP families in Homo sapiens
Experimental identification of homodimerizing B-ZIP families in Homo sapiens
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DOI：
10.1016/j.jsb.2006.02.018
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发表时间：
2006-08-01
影响因子：
3
通讯作者：
Vinson, Charles
中科院分区：
文献类型：
--
作者：
Acharya, Asha;Rishi, Vikas;Vinson, Charles
B-ZIP转录因子的二聚化是由一个平行卷曲螺旋介导的，称为亮氨酸拉链。我们已经评估了七种卷曲螺旋B-ZIP蛋白（ATF 6、XBP、LZIP、NFIL 3、TEF、CREB和C/EBP α）自身和彼此的二聚化特异性。为此，我们设计了显性负性蛋白，称为A-ZIPs，其含有B-ZIP蛋白的亮氨酸拉链二聚化结构域和酸性两亲性N-末端延伸。A-ZIPs以亮氨酸拉链依赖性方式与B-ZIP蛋白异二聚化。假设酸性N-末端延伸与碱性区域形成异二聚体卷曲螺旋结构，基本上将亮氨酸拉链拉入碱性区域。我们现在提出了一个新的酸性延伸设计，稳定异源二聚体与B-ZIP蛋白高达11千卡摩尔（-1）。我们已经使用这些A-ZIP蛋白在竞争EMSA中评估哪一个A-ZIP可以阻止哪一个B-ZIP域的DNA结合。DNA结合的抑制被解释为表明A-ZIP与B-ZIP结构域形成异源二聚体，从而阻止B-ZIP与DNA结合。所有检查的亮氨酸拉链都可以同二聚化，两对（CREB & NFIL 3和ATF 6 & XBP）可以异二聚化。我们讨论这些结果与参考的亮氨酸拉链区的氨基酸序列。这些A-ZIP试剂可能在生物系统中具有抑制特定B-ZIP家族的DNA结合和转录潜力的价值。爱思唯尔公司出版
B-ZIP transcription factors dimerization is mediated by a parallel coiled-coil termed the leucine zipper. We have evaluated the dimerization specificity of the seven coiled-coil B-ZIP proteins (ATF6, XBP, LZIP, NFIL3, TEF, CREB, and C/EBP alpha) with themselves and each other. To do this, we designed dominant negative proteins, termed A-ZIPs, that contain the leucine zipper dimerization domain of a B-ZIP protein and an acidic amphipathic N-terminal extension. The A-ZIPs heterodimerize with B-ZIP proteins in a leucine zipper-dependent manner. The acidic N-terminal extension is hypothesized to form an heterodimeric coiled-coil structure with the basic region, essentially zippering the leucine zipper into the basic region. We now present a new acidic extension design that stabilizes heterodimerization with B-ZIP proteins up to 11 kcal mol(-1). We have used these A-ZIP proteins in a competition EMSA to evaluate which A-ZIP can prevent DNA binding of which B-ZIP domain. Inhibition of DNA binding is interpreted to indicate that the A-ZIP is forming a heterodimer with the B-ZIP domain and thus prevents the B-ZIP from binding to DNA. All leucine zippers examined can homodimerize and two pairs (CREB & NFIL3 and ATF6 & XBP) can heterodimerize. We discuss these results with reference to the amino acid sequence of the leucine zipper region. These A-ZIP reagents may be of value in biological systems to inhibit the DNA binding and transcriptional potential of specific B-ZIP families. Published by Elsevier Inc.