Compartmentalized protein localization in photoreceptors

摘要 视网膜中的光感受器细胞是高度极化和区室化的神经元。大多数蛋白质 定位于光感受器中的特定区室，并且这种区室特异性蛋白定位 对于光感受器的正常功能和存活至关重要。尽管进行了大量的研究， 然而，我们对光感受器实现隔室特异性的机制的理解， 蛋白质定位是有限的。与此相关的是，视网膜变性引起的病理生理学， 这些机制的破坏也没有得到充分的理解。部分原因是缺乏 易于使用的手段来监测蛋白质运输和限制在患病的光感受器。解决 为了满足这一需要，我们开发了两种转基因小鼠品系，iROSRePT（外部基因的诱导型报告基因）， 片段更新和蛋白质运输）和iRATProx（ABCA 4运输和蛋白质运输的诱导型报告基因） 接近标记）。在拟议的研究中，我们将利用这些报告细胞系和四种疾病模型 代表睫状门、鞭毛内转运（IFT）和胞吐膜融合的破坏 机械和调查这些机制的确切要求，为分隔 光感受器中的蛋白质定位。我们预计，这项研究的结果将大大推进 我们对获得感光细胞室稳态的机制的理解， 视网膜变性的病理生理学与有缺陷的蛋白质运输和限制有关。这 这些知识将为开发治疗睫状体相关视网膜变性和评估 新开发的治疗方法的有效性。

ABSTRACT Photoreceptor cells in the retina are highly polarized and compartmentalized neurons. Most proteins localize to a specific compartment in photoreceptors, and such compartment-specific protein localization is essential for the proper function and survival of photoreceptors. Despite considerable research efforts, however, our understanding of the mechanisms by which photoreceptors achieve compartment-specific protein localization is limited. Related to this, the pathophysiology of retinal degenerations caused by the disruption of these mechanisms is also not sufficiently understood. This is partly because of the lack of easy-to-use means to monitor protein trafficking and confinement in diseased photoreceptors. To address this need, we have developed two transgenic mouse lines, iROSRePT (inducible Reporter for the Outer Segment Renewal and Protein Trafficking) and iRATProx (inducible Reporter for ABCA4 Trafficking and Proximity labeling). In the proposed studies, we will utilize these reporter lines and four disease models representing the disruption of the ciliary gate, intraflagellar transport (IFT), and exocytotic membrane fusion machinery and investigate the precise requirements of these mechanisms for the compartmentalized protein localization in photoreceptors. We anticipate that the outcome of this study will significantly advance our understanding of the mechanisms by which photoreceptor compartment homeostasis is attained and the pathophysiology of retinal degenerations linked to defective protein trafficking and confinement. This knowledge will build a foundation to develop treatments for cilia-related retinal degenerations and assess the efficacy of newly developed therapies.