核糖体小亚基蛋白GMP4/RPSx调控PKS5介导的植物ABA反应的分子机制

不同水平调控机制研究是揭示植物响应外界信号分子机理的重要途径。前期研究发现蛋白激酶PKS5可通过翻译后和转录水平调控机制响应外界信号。本组新近发现核糖体小亚基蛋白基因GMP4/RPSx作为激活型突变体pks5-4的遗传抑制子参与抵御ABA信号，并且这一过程很可能通过影响PKS5互作因子PIP158等蛋白质的生物合成得以实现，但GMP4/RPSx响应ABA的调控机制尚未明晰。本项目拟在此基础上，通过蛋白质亚细胞定位、蛋白质翻译后修饰情形鉴定、IP-MS核糖体组成蛋白类别鉴定、IP Ribo-seq和OPP-ID等分析技术，探寻GMP4/RPSx响应ABA信号后从翻译水平对PKS5介导的ABA反应调控的分子机理。这不仅有助于获得核糖体蛋白功能发挥与植物响应ABA信号相互关联的实验证据，而且有助于揭示翻译水平调控机制调节PKS5介导的植物ABA反应的分子机理，进而为耐逆作物分子育种增添知识储备。

Determining the multidimensional mechanism is one of the most important progresses to understand plants’ response to environmental stimuli. Previous study revealed that many regulating levels are involved in PKS5 (SOS2-Like Protein Kinase 5) mediated signaling in response to abiotic stress, such as at transcriptional and post-translational levels. Our recent data indicate that a suppressor of pks5-4, GMP4/RPSx (Genetic Modifier 4 of pks5-4), have key roles in plant ABA responses. Furthermore, the biosynthesis of a novel family of PKS5 interacting proteins PIP158 (PKS5 Interacting Protein 158) is affected by GMP4/RPSx included ribosomes . However, the underlying mechanism of GMP4/RPSx in response to ABA remains enigmatic. Based on above progresses, this project is attempted to determine the molecular basis of GMP4/RPSx in PKS5 mediated ABA signaling. To accomplish it, we will adopt many techniques, i.e. subcellular localization determination, protein modifications’ identification, IP(Immunoprecipitated)-MS(Mass Spectrometry) based ribosome composition identification, IP Ribo-seq and OPP-ID (O-propargyl-Puromycin-associated Nascent Chain Proteomics Identification). When fulfilled, it is hopeful to understand the relationship between the biological significance of ribosomal proteins and plant responses to ABA. Moreover, it is also hopeful to determine the translational mechanism of PKS5 mediated ABA signaling and provide novel insight into tolerant oriented crop development.