Modeling Cell Regulatory Networks

描述(申请人提供)：这个项目的总体目标是开发细胞信号网络的详细空间模型，以了解信号组件微域的起源和动态。我们将把在虚拟细胞程序中开发的空间逼真模型与实验相结合，以了解微域的特征。拟议的项目基于以下中心假设：“空间局部化的动态以及监管机构的活动将有助于信令网络内信息流的幅度和位置”。为了验证这一假设，我们在神经细胞中建立了一个由cAMP和MAP-K1、2通路组成的简单网络。利用这个网络，我们将确定系统的关键上游刺激成分的位置、浓度和活性状态在激活的MAP-K1、2的空间定义域的形成中的作用。具体问题包括不同水平的β-肾上腺素能受体占据对MAP-K激活的程度以及活性MAP-K1的空间域的影响；在β-肾上腺素能受体与腺酰环化酶5和2的偶联过程中，Gs的GTP酶活性速率的变化，以及随后激活的MAP-K1，2的空间域的特征，以及不同水平的蛋白激酶A对MAP-KK活性的范围和空间定位的影响。我们还将确定信号网络的负调控因子，如磷酸二酯酶和蛋白磷酸酶在确定激活的MAPK空间域的特征中的作用1，2我们将通过分析树突长度与到细胞体的距离以及树突的长宽比在确定激活的MAPK空间域中的关系来研究细胞形态在确定空间域中的作用。从这样的分析中，我们希望定义确定细胞内信号分子微域特征所涉及的关键标准。

DESCRIPTION (provided by applicant): The overall goal of this project is to develop detailed spatial models of cell signaling networks to understand the origins and dynamics of microdomains of signaling components. We will combine spatially realistic models developed in the program Virtual Cell with experiments to understand the characteristics of microdomains. The proposed project is based on the following central hypothesis: "the dynamics of spatial localization as well as activity of the regulators will contribute to amplitude and location of information flow within the signaling network". To test this hypothesis we have set up a simple network consisting of camp and MAP-kinase 1, 2 pathways in neuronal cells. Using this network we will determine the role of the location, concentrations and activity state of key upstream stimulatory components of the systems in the development of spatially defined domains of activated MAP-kinase 1,2. Specific questions include the effect of varying levels of beta-adrenergic receptor occupancy on the extent of MAP-kinase activation as well as the spatial domains of active MAP-kinase; the effect of varying GTPase activity rates of Gs in the coupling of beta-adrenergic receptor to adenylyl cyclases 5 and 2, and the consequent characteristics of the spatial domains of activated MAP-kinase 1,2 and the effect of varying levels of activation of protein kinase A on the extent and spatial localization of MAP-kinase activity. We will also define the role of negative regulators of the signaling network, such as phosphodiesterases and protein phosphatases in determining the characteristics of the spatial domains of activated MAP-kinases 1,2 We will study the role of cellular morphology in defining spatial domains by analyzing the relationship between the length of dendrites and distance from the cell body as well as the length to breadth ratios of dendrites in determining the spatial domains of activated MAPkinase. From such analysis we hope to define the key criteria involved in determining the characteristics of microdomains of signaling molecules within the cell.