【作者】 李驰峻；

【导师】 种康； 许智宏；

【作者基本信息】 中国科学院研究生院（植物研究所） ， 植物学， 2006， 博士

【摘要】 SKP1 (S-phase kinase-associated-protein 1)家族蛋白是普遍存在于真核生物中的一类小分子量蛋白质,其主要的生物学功能在于参与SCF复合体的形成,从而调控生物体内泛素介导的蛋白质降解,并参与多方面的生物发育过程。SKP1蛋白能够同时和Cullin蛋白以及F-box蛋白结合,形成SCF复合体的核心部分。因此,SKP1正常功能的维持对于SCF复合体功能的实现至关重要。研究显示,植物中尤其是以拟南芥为代表模式植物中已经发现了21个SKP1基因成员,并发现其中的ASK1参与了多个SCF复合体的形成并调控着包括植物雄性减数分裂、生长素、赤霉素、茉莉酸和乙烯等生理和发育进程。但是来自高等植物尤其是小麦和水稻中的SKP1基因还鲜有报道,其功能还不为所知;此外,SKP1基因与ABA的关系还没有任何报道。本文利用筛选小麦减数分裂期小花的cDNA文库结合RT-PCR的方法从小麦中分离到了一个SKP1同源基因,并命名为TSK1 (Triticum aestivum SKP1-Like 1)。序列比较结果显示TSK1与多个植物来源的SKP1基因有较高的同源性,对其推测的编码蛋白序列的分析发现TSK1与包括拟南芥来源的ASK1/ASK2等蛋白的羧基端存在非常高的保守性。在对TSK1表达模式的研究中,本文发现TSK1主要是集中在小麦花序和幼根中表达。利用多种激素对小麦幼苗处理之后,发现TSK1的表达受ABA的抑制,但是当小麦中ABA合成受抑的情况下,TSK1的表达会有所增加,说明TSK1的表达受ABA的调控。RNA原位杂交显示TSK1基因在花顶端分生组织、花药以及幼根等分生较旺盛的组织中有较强的表达,暗示该基因可能参与了与细胞分裂相关的过程。为了研究TSK1可能具有的功能,本文首先在ask1-1突变体背景上超表达TSK1,发现能够部分恢复ask1-1突变体雄性不育的表型,说明TSK1和ASK1更多还原

【Abstract】 SKP1, S-phase kinase-associated-protein 1, was shown to be a component of a SCF (SKP1-Cullin-F-box) complex, which is necessary for ubiquitin-mediated protein degradation in eukaryotes. The SCF complex is composed of 4 major subunits: Cullin (CDC53 in yeast), SKP1, a RING finger protein (RBX1/HRT1/ROC1) and an F-box protein. Among them, SKP1 acts as an adaptor to link Cullin1 (Cul1) to F-box protein, which specifically recognizes different target proteins via a variable C-terminal domain and interacts with SKP1 through an N-terminal structural motif. A number of SKP1-like genes are found in plants, but only ASK1 (Arabidopsis SKP1-like 1) and ASK2 have been characterized genetically. In Arabidopsis, many F-box proteins were found to interact with ASK1 or ASK2, which suggests that they could form various SCF complexes, and evidence indicated that SCF complexes regulate plant development by affecting the signal pathways of auxin, gibberellin, and ethylene. Until now, little is known about the SKP1 genes in monocots and the relationship between SKP1 protein and ABA signaling.Here, we report on a SKP1-like gene from winter wheat named TSK1 (Triticum aestivum SKP1-Like 1). Expression analysis revealed that it was expressed predominantly in young roots and floral buds but repressed by abscisic acid (ABA) treatment. RNA in situ hybridization showed it is expressed in shoot apical meristems (SAMs) and anthers, especially the tapetum and microsporocytes at the meiosis stage.更多还原