Genetics of Endocytic Trafficking in the Drosophila Eye

描述（由申请人提供）：细胞持续吸收营养， 信号分子注定要降解的内化蛋白质 从质膜通过早期内体，多泡体（MVB）， 晚期内体，最后到溶酶体。的分子调控机制 内吞运输中的这些步骤是重要的，因为它们被 许多遗传性疾病，包括Chediak-Fligashi或Hermansky-Pudlak综合征。 果蝇复眼是一个很好的遗传分析模型系统 内吞运输这一过程所必需的许多基因突变 可以被识别为眼睛颜色突变，因为它们也会干扰 将生物合成货物递送至色素颗粒。老板的内化 配体进入R7光感受器细胞提供了直接测定， 贩卖人口该提案旨在利用 果蝇眼内吞运输的遗传解剖 多细胞生物 深橙子和康乃馨眼睛颜色基因编码两个亚基 在溶酶体传递和眼睛色素沉着的后期所必需的复合物。 在特异性目的1中，该复合物的额外亚基在溶酶体中的作用 交付将被表征。在具体目标2中， 将确定DOR突变细胞内吞和生物合成运输 在超微结构水平上，用HRP融合标记不同的区室 proteins. 利用溶酶体传递和眼睛颜色之间令人兴奋的联系 突变，具体目标3提出了一个系统的筛选突变体影响 眼睛颜色和内吞运输。除了额外的dor-like突变 在通路的后期起作用，这种筛选也会产生干扰的突变。 与内吞运输的早期步骤，例如，MVB的调节 生物起源和功能。具体目标4提出了以下特征： DmVps 28作为这样的突变的一个例子，作用于内吞途径的早期。 这项工作的一个重要的长期目标是将不同的缺陷 在遗传性疾病中将突变运输到症状中， 贩卖人口为了直接比较果蝇模型系统中的表型， 具体目标5旨在分离果蝇中的突变 Hermansky-Pudlak综合征-1基因及其产生的特征 内吞运输的缺陷。

DESCRIPTION (provided by applicant): Cells continuously take up nutrients and signaling molecules. Internalized proteins destined for degradation are routed from the plasma membrane through early endosomes, multivesicular bodies (MVBs), late endosomes and finally to lysosomes. The molecular mechanisms regulating these steps in endocytic trafficking are important, because they are altered by many genetic diseases including Chediak-Fligashi or Hermansky-Pudlak syndromes. The Drosophila compound eye is an excellent model system for a genetic analysis of endocytic trafficking. Mutations in many genes necessary for this process can be identified as eye color mutations because they also interfere with the delivery of biosynthetic cargo to pigment granules. Internalization of the Boss ligand into R7 photoreceptor cells provides a direct assay to follow endocytic trafficking. This proposal is aimed at exploiting these features of the Drosophila eye for a genetic dissection of endocytic trafficking in multicellular organisms. The (dor) deep orange and (car) carnation eye color genes encode two subunits of a complex that is necessary late in lysosomal delivery and eye pigmentation. In Specific Aim 1, the rote of additional subunits of this complex in lysosomal delivery will be characterized. In Specific Aim 2, the specific defects in endocytic and biosynthetic trafficking in dor mutant cells will be determined on the ultrastructural level by labeling different compartments with HRP fusion proteins. To exploit the exciting connection between lysosomal delivery and eye color mutations, Specific Aim 3 proposes a systematic screen for mutants affecting eye color and endocytic trafficking. Besides additional dor-like mutations acting late in the pathway, this screen will also yield mutations interfering with earlier steps in endocytic trafficking, for example, the regulation of MVB biogenesis and function. Specific Aim 4 proposes the characterization of DmVps28 as an example for such mutations acting early in the endocytic pathway. An important long-term goal of this work is to relate defects in different trafficking mutations to the symptoms in genetic diseases altering endocytic trafficking. To directly compare phenotypes in the Drosophila model system, Specific Aim 5 is directed towards the isolation of mutations in the Drosophila Hermansky-Pudlak syndrome-1 gene and the characterization of the resulting defects in endocytic trafficking.