Stochastic Modeling of Protein Interactions in the Endoplasmic Reticulum

描述（由申请人提供）：大多数细胞功能由蛋白质-蛋白质相互作用介导。这些相互作用的控制直接通过蛋白质活性的特异性实现，并通过与伴侣辅因子的选择性相互作用间接实现。传统上，瞬时相互作用的定量数据来自体外测定，其中伴侣蛋白的相互作用与其他细胞因子分离。当将这些数字外推到体内条件时，通常假设蛋白质环境是均匀的。然而，很明显，这些相互作用的动态性质创造了亚细胞器的蛋白质池。复杂异质环境对细胞功能的动态影响尚未得到充分定量，其中蛋白质伴侣的局部浓度将不同于其在细胞中的总体浓度。 本研究提案的重点是这些局部环境对细胞蛋白质折叠细胞器--内质网（ER）作用的影响。利用新兴的定量荧光显微镜技术，数学建模和酵母遗传学相结合，拟议的研究将定量确定BiP，居民ER hsp 70伴侣蛋白的蛋白质-蛋白质相互作用的作用，其定位和功能。不正确折叠的蛋白质和蛋白质未能穿过分泌的早期步骤与糖尿病，囊性纤维化和几种神经系统疾病有关。该提案将生物科学家与工程师结合起来，以发展对细胞网络的基本理解，并创建一种解释分泌缺陷的方法。此外，这项研究将提供深入了解特定的细胞功能的分泌过程中，一直难以解决的传统生化方法。

DESCRIPTION (provided by applicant): The majority of cellular functions are mediated by protein-protein interactions. Control of these interactions Is achieved directly from specificity of protein activity and indirectly though selective interactions with partner co-factors. Traditionally quantitative data on transient interactions comes from an in vitro assay where the interactions of partner proteins are isolated from other cellular factors. When extrapolating these numbers to in vivo conditions it is usually assumed that the protein milieu is homogenous. Yet it is clear that the dynamic nature of these interactions creates suborganellar pools of proteins. The dynamic effect of complex heterogeneous environments on cellular function has not been adequately quantitated, where local concentrations of protein partners will be different from their overall concentration in the cell. This research proposal focuses on the effects of these localized environments on the action of the cellis protein folding organelle, the endoplasmic reticulum (ER). Utilizing a combination of emerging quantitative fluorescent microscopy techniques, mathematical modeling and yeast genetics, the proposed research will quantitatively determine the role of the protein-protein interactions of BiP, the resident ER hsp70 chaperone, on its localization and function. Improperly folded proteins and the failure of proteins to traverse the early step of secretion is linked to diabetes, cystic fibrosis, and several neurological diseases. This proposal integrates biological scientists with engineers to develop a fundamental understanding of cellular networks and create a methodology to explain deficiencies in secretion. In addition, this research will provide insight to specific cellular functions important for the secretory process that have been difficult to address by traditional biochemical methods.