A SAM domain network in Polycystic Kidney Disease

描述(申请人提供)：多囊肾病(PKD)是最常见的致命性遗传病之一。Bicc1和Samcystin/ANKS6的不育Alpha基序(SAM)结构域的突变被认为是导致人类、大鼠或小鼠囊性疾病的未知机制。以前的工作和我们自己的初步结果已经在Bicc1，ANKS6的SAM结构域和我们鉴定的一种名为Anks3的新蛋白质之间建立了相互作用网络。Bicc1调节细胞的极性和几种已知与PKD有关的蛋白质的表达。Anks3和ANKS6都与关键调控蛋白Bicc1结合，这一事实表明它们可能对Bicc1的功能起重要作用。我们提出了两个主要的假设：(1)ANKS6和Anks3可以单独或通过SAM结构域的相互作用共同调节Bicc1的功能。(2)新发现的Anks3蛋白对PKD的发生发展具有调控作用。目的1.从物理和结构上研究SAM介导的Bicc1、ANK3和ANKS6的相互作用。了解复合体的结构对于理解SAM结构域突变的生物学后果将是重要的。目的2.在细胞检测中验证Anks3和ANKS6调节已知Bicc1功能的假设。我们将研究ANKS3和ANKS6对Bicc1的细胞定位、蛋白表达和Wnt信号的影响。目的3.验证Anks3基因突变可在转基因大鼠体内产生PKD的假设。在Anks3过度表达或缺失的情况下，将创造转基因大鼠品系，并检查其是否发生囊性疾病。我们还将研究这些变化如何影响ANKS6突变大鼠的PKD发展。该项目有可能解释几种致病突变的机制，确定参与PKD的蛋白质的功能，并确定PKD复杂途径中的新参与者。

DESCRIPTION (provided by applicant): Polycystic kidney disease (PKD) is one of the most common lethal genetic diseases. Mutations in the Sterile Alpha Motif (SAM) domains of Bicaudal-C (Bicc1) and Samcystin/Anks6 are known to cause cystic disease in humans, rats or mice by unknown mechanisms. Prior work, and our own preliminary results, have established an interaction network between the SAM domains of Bicc1, Anks6 and a new protein we have identified called Anks3. Bicc1 regulates cell polarity and the expression of several proteins known to contribute to PKD. The fact that both Anks3 and Anks6 bind to the key regulatory protein Bicc1, suggests that they may be important for Bicc1 function. We propose to test two primary hypotheses: (1) That Anks6 and Anks3 can modulate the functions of Bicc1 either separately or together via there SAM domain interactions. (2) That the newly identified Anks3 protein can modulate the development of PKD. Aim 1. We will physically and structurally characterize the SAM mediated interactions of Bicc1, Ank3 and Anks6. An understanding of the architecture of the complexes will be important for understanding the biological consequences of SAM domain mutations. Aim 2. Test the hypothesis that Anks3 and Anks6 modulate known Bicc1 functions in cellular assays. We will examine the effects of Anks3 an Anks6 on cellular localization of Bicc1, protein expression and Wnt signaling. Aim 3. Test the hypothesis that Anks3 mutations can generate PKD in transgenic rats. Transgenic rat strains will be created where Anks3 is over-expressed or deleted and examined for the development of cystic disease. We will also study how these alterations affect the development of PKD in Anks6 mutant rats. The project has the potential to explain the mechanism of several disease-causing mutations, identify functions of proteins involved in PKD, and identify a new player in the complex pathway to PKD.