The role of light in Caulobacter growth and development

描述（由申请人提供）：这项工作的目标是了解细胞周期控制的分子决定因素，这直接关系到人类健康的许多方面，包括癌症生物学。在新月形茎杆菌中，细胞周期主要由双组分信号转导系统指导，该系统由传感器组氨酸激酶及其同源反应调节因子组成。Caulobacter基因组包含一个与光传感器型LOV结构域偶联的组氨酸激酶（以下称为LOV激酶）。这种LOV激酶的转录受细胞周期控制，在DNA复制开始时达到峰值。因此，光可能在调节复制或细胞生长和发育的某些其他方面发挥作用。我将通过三个途径来完成这个项目：1)在体外和体内表征LOV激酶的光活性和光谱特性；2)表征LOV激酶敲除菌株在有光和无光条件下的表型和表达谱；3)结合亲和纯化、质谱分析和体内荧光共振能量转移（FRET）来鉴定LOV激酶细胞信号网络的其他组成部分。

DESCRIPTION (provided by applicant): The goal of this work is to understand the molecular determinants underlying cell cycle control, which directly relates to many aspects of human health including cancer biology. In Caulobacter crescentus, the cell cycle is largely directed by two-component signal transduction systems consisting of sensor histidine kinases and their cognate response regulators. The Caulobacter genome contains a histidine kinase coupled to a photosensor-type LOV domain (hereafter known as LOV kinase). Transcription of this LOV kinase is cell cycle-controlled, peaking at the beginning of DNA replication. Thus, light may have a role in regulation of replication or some other aspect of cellular growth and development. I will approach this project via three routes: 1) characterize the photoactivity and spectral properties of LOV kinase in vitro and in vivo; 2) characterize the phenotype and expression profile of a LOV kinase knockout strain in the presence and absence of light; 3) identify other components of the LOV kinase cellular signaling network using a combination of affinity purification, mass spectrometry, and in vivo fluorescence resonance energy transfer (FRET).