Light stress proteins from the chlorophyll a/b-binding gene family in Arabidopsis thaliana

高等植物和绿色藻类中的捕光叶绿素a/b结合蛋白家族由20多个与光系统I和II相关的不同成员组成。此外，这个家族的几个远亲保守的叶绿素结合残基和一个短暂的表达模式有关的各种压力条件已被报道。这些远亲包括：三螺旋Elips（早期光诱导蛋白）和相关蛋白，两螺旋Seps（应激增强蛋白）和一螺旋Ohps（一螺旋蛋白）。虽然在环境光条件下没有检测到Elips，但在不存在光胁迫的情况下存在显著量的Seps和Ohps，但在叶片暴露于高强度光后，它们的水平急剧增加。在过去的几年里，我们的兴趣集中在两个这样的蛋白质，Sep 2和Ohp 2。我们希望继续研究这些蛋白在拟南芥中的位置和功能，并通过包括另外两个成员Sep 3和Ohp 1来扩大我们的分析。我们计划过表达和提高Sep 3和Ohp 1的多克隆抗体，并用分离的色素重建过表达的蛋白质。将通过类囊体膜的亚分级进行定位研究，并使用交联或表面等离子体共振技术（Biacore）分析蛋白质-蛋白质相互作用。反向遗传学（分析“敲除”，“敲低”突变体和转基因）将被应用于解开这些蛋白质在叶绿体中的功能。

The family of light-harvesting chlorophyll a/b-binding proteins in higher plants and green algae is composed of more than 20 different members associated with photosystem I and II. In addition, several distant relatives of this family with conserved chlorophyll-binding residues and a transient expression pattern related to various stress conditions have been reported. These distant relatives include: three-helix Elips (early light-induced proteins) and related proteins, two helix Seps (stress-enhanced proteins) and one-helix Ohps (one-helix proteins). While Elips are not detected under ambient light conditions, a significant amount of Seps and Ohps is present in the absence of light stress but their level increases drastically after exposure of leaves to high intensity light. In the past years our interest was focused on two such proteins, Sep2 and Ohp2. We would like to continue studies on location and function(s) of these proteins in Arabidopsis thaliana and broaden our analysis by including two additional members, Sep3 and Ohp1. We plan the overexpression and raising polyclonal antibodies for Sep3 and Ohp1 and reconstitution of overexpressed proteins with isolated pigments. Localization studies will be performed by subfractionation of thylakoid membranes and protein-protein interaction will be analyzed using crosslinking or a surface plasmon resonance technology (Biacore). Reverse genetics (analysis "knock out", "knock down" mutants and transgenics) will be applied to unravel the function of these proteins in the chloroplast.