Mouse Models of Parkin Biology and Pathobiology

Parkin基因突变是常染色体隐性遗传性帕金森病(PD)的主要遗传原因，Parkin基因突变在家族性PD中也起重要作用。初步研究表明，Parkin通过作为泛素E3连接酶在泛素蛋白酶体途径(UPP)中发挥潜在的关键作用。大多数帕金森病的致病突变被认为是功能突变的丧失，最终导致泛素化的缺失和 UPP介导的帕金底物降解的后续失败。因此，Parkin底物的异常堆积被认为在Parkin突变患者黑质多巴胺能神经元的死亡中发挥了作用。一些可能的Parkin底物已被鉴定，但它们在Parkin突变引起的帕金森病发病机制中的重要性尚不清楚。我们建议用Parkin基因敲除小鼠的特征来正式检验这一假说 帕金功能缺失是帕金突变引起的帕金森氏病的原因。此外，Parkin基因敲除小鼠的生化和蛋白质组学特征可能有助于揭示Parkin基因突变导致的帕金森病发病机制中的重要底物。因此，有必要通过实验进一步研究parldN及其底物在帕金森病发病机制中的作用。在特定的目标#1中，我们将描述Parkin基因敲除小鼠的特征。在特定目标#2中，我们将评估Parkin基因敲除对环境毒素的敏感性。在特定的目标#3中，我们将评估parkin与α-突触核蛋白相互作用蛋白synPhilin-1的相互作用，并确定parkin是否介导K48或K63泛素连接。在特定的目标#4中，我们将通过评估parkin基因敲除小鼠与A53T突变的α-突触核蛋白转基因小鼠的杂交效果来确定parkin是否与α-突触核蛋白相互作用，并进一步评估parkin与α-突触核蛋白相互作用蛋白synPhilin-1的相互作用。 在特定的目标#5中，我们将识别和表征parkin相互作用蛋白，并识别parkin基因敲除小鼠的代偿性变化。Parkin基因敲除的发展和特征，了解Parkin、α-突触核蛋白和SynPhilin-1在PD发病机制中的关系可能有助于深入了解这些基因敲除的分子机制 基因产物可诱导神经元损伤，并可能提供新的治疗方法和靶点，以防止这些家族相关基因在帕金森病退变过程中的毒性作用。

Mutations in the parkin gene are the main genetic cause of autosomal recessive Parkinson's disease (PD) and mutations in parkin also play a major role in familial PD. Preliminary studies indicate a potential pivotal role for parkin in the ubiquitin proteasomal pathway (UPP) by functioning as an ubiquitin E3 ligase. Most disease causing mutations of parkin are thought to be loss of function mutations that ultimately lead to the absence of ubiquitination and the subsequent failure of UPP-mediated degradation of parkin substrates. Thus, the abnormal accumulation of parkin substrates is thought to play a role in the demise of substantia nigra dopaminergic neurons in patients with parkin mutations. A number of putative parkin substrates have been identified, but their importance in the pathogenesis of PD due to parkin mutations is not known. We propose to characterize parkin knockout mice to formally test the hypothesis that the absence of parkin function is the cause of PD due to parkin mutations. Furthermore, biochemical and proteomic characterization of the parkin knockout mice may shed light on the substrates that are important in the pathogenesis of PD due to parkin mutations. Accordingly experiments are proposed to further characterize the role of parldn and it's substrates in the pathogenesis of PD. In Specific Aim #1 we will characterize parkin knockout mice. In Specific Aim #2 we will evaluate the sensitivity of parkin knockouts to environmental toxins. In Specific Aim #3 we will evaluate the interaction of parkin with the alpha-synuclein interacting protein, synphilin-1 and determine whether parkin mediates K48 or K63 ubiquitin linkages. In Specific Aim #4 we will determine whether parkin interacts with alpha-synuclein by evaluating of the effect of crossing parkin knockout mice with A53T mutant alpha-synuclein transgenic mice and further evaluate the interaction of parkin with the alpha-synuclein interacting protein, synphilin-1. In Specific Aim #5 we will identify and characterize parkin interacting proteins and identify compensatory changes in parkin knockout mice. Development and characterization of parkin knockout, understanding the relationship of parkin, alpha-synuclein and synphilin- 1 in the pathogenesis of PD may provide insight into the molecular mechanisms by which these gene products induce neuronal damage and may provide novel therapeutics and targets to prevent the toxic effects of these familial associated genes in the degenerative process of PD.