Construction Of Rice Heterotrimeric G Protein Interaction Network

In mammalian and plant, heterotrimeric G-proteins regulate a wide range of the life process by mediating various signaling pathways. Compared to mammalian, plant G proteins complex are much simpler. Studies of plant G proteins have been more concentrated on the dicotyledon model plant Arabidopsis thaliana, less on the monocotyledon model plant rice. In this study, G protein In this study, we established the protein-protein interaction network of G protein by bioinformatics, cell biology, and molecular biochemistry approaches. The main results were as follows:1、I used yeast two hybrid system to screen the interaction proteins of G protein from cDNA library of rice leaf. I found that RGA1interact with PsbP and Rpe, RGG1interact with CAB. These interacted proteins relate to photosynthesis. This data indicate that G protein could regulate photosynthesis in rice. Moreover, I found that RGG1could interact with LTP family proteins which related to disease-resistant.2、I discovered that DEP1and depl could interact with RGG1. In addition, DEP1and its mutant depl could interact with photosynthesis related protein PsbP, plastocyanin and glycolysis related protein glyceraldehyde-3-phosphate dehydrogenase. All of these proteins could interact with RGG1too. This result indicates that DEP1and RGG1have the same function in some signaling pathway, and DEP1N-terminal y-domain is the functional domain to regulate these signaling pathways.3、I also use yeast two hybrid system and His pull-down to screen the interaction proteins of OsRACK1protein from cDNA library of rice leaf, and to find some relationship between OsRACK1and G protein. The result showed that we found one protein TPR could interact with RACK1as well as RGG1. TPR could interact with ethylene’s receptor. So this indicates that G protein may together with RACK1to form a complicated signaling component to regulate ethylene signaling pathway.