Photoreceptor Synaptic Ribbon Associated Proteins

这项研究检查了视网膜中参与视觉的分子。视网膜是一层薄薄的神经细胞，位于眼睛后部，有五层厚。它处理有关光的信息并将其发送给大脑。本研究中研究的分子是视网膜中特殊的蛋白质，在光感受器细胞检测到光的第一个点时，参与发出光存在或不存在的信号。这些蛋白质在光感受器中构成了一种叫做突触带的微观结构。关于光的存在或不存在的信号通过突触带以一种未知的方式传递给下一层细胞。拟议的工作将调查这一机制。我们已经为这个蛋白质家族制作了特殊的标记。每个标记都以特定的重量附着在蛋白质上，这是我们用来区分蛋白质的特性之一。其中一种被称为b16抗体的标记物可以识别一种仅在视网膜中发现的罕见蛋白质，这种蛋白质的重量为54kD。我们最近成功地将54kD蛋白从其余的视网膜中分离出来。我们现在将对它的氨基酸进行排序，作为识别它和理解这种蛋白质功能的一种方式。第二组实验将检查与我们的B16标记识别的蛋白质相关的其他蛋白质。其中一种称为局灶黏附蛋白，可能参与保持突触带附着在突触前膜上。这是信息传递给视网膜下一组细胞的地方。在第三组实验中，我们将使用电子显微镜来观察这些蛋白质在突触带中的位置。至关重要的是，我们证明这些蛋白质是突触带的一部分，位于突触前末端，而不是突触后到光感受器或细胞外空间。此外，我们将用其他生化方法检查与突触带相关的其他蛋白质。当所有的实验完成后，我们期望有：1)确定我们的B16标记识别的蛋白质，2)了解这个家族中其他相关蛋白质的身份，以及3)表明B16标记附着在突触带中不可或缺的蛋白质上。这将推进我们对突触带是由什么组成以及它是如何工作的基本知识。

This research examines molecules in the retina that participate in sight.The retina is a thin sheet of nerve cells at the back of the eye that is fivelayers thick. It processes information about light and sends it to the brain.The molecules studied in this research are special proteins in the retinainvolved in signaling the presence or absence of light at the first point atwhich light is detected in the photoreceptor cell. The proteins make up amicroscopic structure in the photoreceptor called the synaptic ribbon.Signals about the presence or absence of light are transmitted to the nextlayer of cells by using the synaptic ribbon in an unknown way. The proposedwork will investigate this mechanism.We have made special markers for this family of proteins. Each markerattaches to proteins with specific weights, which is one of the properties weuse to tell the proteins apart. One of these markers, called the B16antibody, recognizes a rare protein found only in the retina that weighs 54kD.We have recently succeeded in separating the 54kD protein from the rest of theretina. We will now sequence its amino acids as a way of identifying it andunderstanding the function of this protein. The second group of experiments will examine other proteins are related tothe one recognized by our B16 marker. One of these, called a focal adhesionprotein, may be involved in keeping the synaptic ribbon attached to thepresynaptic membrane. This is the place where information is transmitted tothe next group of cells in the retina.In the third group of experiments we will use the electron microscope to lookat the position of these proteins within the synaptic ribbon. It is criticalthat we demonstrate that the proteins are part of the synaptic ribbon withinthe presynaptic terminal not postsynaptic to the photoreceptor or in theextracellular space. In addition, we will examine the other proteinsassociated with the synaptic ribbon with other biochemical methods. When all the experiments are finished, we expect to have: 1) identified theprotein that our B16 marker recognizes, 2) learned the identity of the other,related proteins in this family, and 3) shown that the B16 marker attaches toa protein that is integral to the synaptic ribbon. This will advance ourfundamental knowledge about what the synaptic ribbon is made of and how itworks.