Abstract
Purpose: :
The studies we are performing are intended to: 1. To determine whether the function of Prominin and Spacemaker/EYS is evolutionary conserved between vertebrate and invertebrate photoreceptors cells and provide insights into the disease mechanism of arRP25 and Prominin associated arRP and macular degeneration.
Methods: :
First and foremost we are using Drosophila to define the functional relationship between Spacemaker and Prominin in photoreceptor cell morphogenesis. With the use of biochemical binding assays, an in vitro tissue culture assay and transgenic rescue experiments, we are systematically determining the domains of interaction between the two proteins, the specific domains of each protein required for function, and whether the function of the species specific proteins, human and Drosophila, are evolutionary conserved. Furthermore, we are performing a genetic enhancer screen to uncover downstream and modulators of Spacemaker and Prominin function.
Results: :
In Drosophila, we have demonstrated the Spacemaker interacts with Prominin and together are responsible for not only creating an extracellular matrix that is critical for separating and positioning the light sensing organelles but also for the shaping and modeling of the microvilli. We will present data of protein structure function studies, including an assessment of the minimal portions of Spacemaker/EYS necessary for rescue, and a molecular mechanism detailing the interaction with Prominin. Furthermore, we will present an initial characterization of the targets isolated in our genetic screen and how they potential modulate Spacemaker and Prominin function.
Conclusions: :
The use of an genetic amenable system is and will provide critical insights for understanding the disease mechanism of arRP25 and Prominin associated RP and macular degeneration. In addition, our methodology highlights possible treatments and therapeutic targets not currently obtainable in a mammalian organism.
Keywords: extracellular matrix • photoreceptors • retinitis