Tbx5 and Tbx4 transcription factors interact with a new chicken PDZ-LIM protein in limb and heart development
Tbx5 and Tbx4 transcription factors interact with a new chicken PDZ-LIM protein in limb and heart development
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DOI：
10.1016/j.ydbio.2004.05.024
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发表时间：
2004-09-01
影响因子：
2.7
通讯作者：
Simon, HG
中科院分区：
文献类型：
--
作者：
Krause, A;Zacharias, W;Simon, HG
t结构域转录因子Tbx5和Tbx4在脊椎动物肢体和心脏发育中起重要作用。为了鉴定相互作用和潜在的tbx调节蛋白，我们以Tbx5的c端结构域为诱饵进行了酵母双杂交筛选。我们发现了一个由1个n端PDZ和3个c端LIM结构域组成的新的PDZ-LIM蛋白，我们将其命名为鸡LMP-4。在Tbx2、3、4、5亚家族中，我们观察到与Tbx5和Tbx4蛋白的排他性相互作用。Tbx3和Tbx2均不能替代LMP-4的结合。虽然鸡的LMP-4与Tbx5或Tbx4结合，但它使用不同的LIM结构域与单个蛋白质结合。LMP-4和Tbx蛋白的亚细胞共定位支持蛋白质相互作用，并揭示了LMP-4对Tbx蛋白分布的干扰，将转录因子束缚在细胞骨架上。蛋白-蛋白相互作用表明Tbx在转录因子核定位水平上的功能调控。在鸡肢体和心脏发育过程中，Tbx5/LMP-4和Tbx4/LMP-4在时间和空间上紧密共表达，表明它们在同一途径上起作用。令人惊讶的是，鸡LMP-4在心脏中Tbx5以外的表达域导致Tbx4在该器官的流出道和右心室中表达。表达tbx4的细胞与最近发现的继发性前心形成区一致。Tbx5和Tbx4分别在心脏后部或前部的离散表达域和前肢或后肢的专属表达域，提示心脏和四肢的共同通路。新的tbx5 /4特异性结合因子的发现进一步提示了Tbx转录因子调控发育和疾病的新机制。(C) 2004爱思唯尔公司版权所有。
The T-domain transcription factors, Tbx5 and Tbx4, play important roles in vertebrate limb and heart development. To identify interacting and potential Tbx-regulating proteins, we performed a yeast two-hybrid screen with the C-terminal domain of Tbx5 as bait. We identified a new PDZ-LIM protein composed of one N-terminal PDZ and three C-terminal LIM domains, which we named chicken LMP-4. Among the Tbx2, 3, 4, 5 subfamily, we observed exclusive interaction with Tbx5 and Tbx4 proteins. Tbx3 nor Tbx2 can substitute for LMP-4 binding. While chicken LMP-4 associates with Tbx5 or Tbx4, it uses distinct LIM domains to bind to the individual proteins. Subcellular colocalization of LMP-4 and Tbx proteins supports the protein interaction and reveals interference of LMP-4 with Tbx protein distribution, tethering the transcription factors to the cytoskeleton. The protein-protein interaction indicates regulation of Tbx function at the level of transcription factor nuclear localization. During chicken limb and heart development, Tbx5/LMP-4 and Tbx4/LMP-4 are tightly co-expressed in a temporal and spatial manner, suggesting that they operate in the same pathway. Surprisingly, chicken LMP-4 expression domains outside those of Tbx5 in the heart led to the discovery of Tbx4 expression in the outflow tract and the right ventricle of this organ. The Tbx4-expressing cells coincide with those of the recently discovered secondary anterior heart-forming field. The discrete posterior or anterior expression domains in the heart and the exclusive fore- or hindlimb expression of Tbx5 and Tbx4, respectively, suggest common pathways in the heart and limbs. The identification of a new Tbx5/4-specific binding factor further suggests a novel mechanism for Tbx transcription factor regulation in development and disease. (C) 2004 Elsevier Inc. All rights reserved.