SUMOylation Of PES1and Its Relative Functional Research

Since identified, PES1was confirmed having high conservation and playing an important role in variety species. It is essential for normal growth in yeast. In mammals, PES1can take part in the ribosome biosynthesis associating with UBFI (Upstream binding factor). And the expression of PES1is high in some tissues that have exuberant proliferation, which imply PES1may be functional in cell proliferation and cell cycle. Besides, many cacer cells have high expression of PES1, such as, breast cancer, gastric, prostate cancer. So it is possible that PES1has great effect on the development of cancer.As one of the most important post-transcriptional modification, SUMOylation (Small ubiquition related modifier) can control the function of its target by modulating the cell location and cell stability. The focal point of our research is SUMOylation of PES1and its relative functional regulation. Our research includes:(1) To confirm if PES1can be SUMOylated, COS-7cells were transfacted with PES1and SUMO, and then verified the SUMOylation of PES1by Western Blotting and immunoprecipitation.(2) Identify the SUMOylation site. First, we analyzed the sequence of PES1and found two potential SUMOylation sites. Then we made three mutants by site-directed mutagenesis, obtaining K249R, K517R, and2KR. After that we use Western Blotting and immunoprecipitation again to test if the mutation of potential SUMOylation sites would affect the migrating bands.(3) SUMOylation can affect the cell location and cell stability of target protein, so we next verified these two aspects by using immunofluorescent assay and half-life assay. We found SUMOylation didn’t affect the cell location, but the mutation of SUMO sites can decrease the stability of PES1. cccccccccccccc(4) Last we studied the SUMOylation of PES1relative functional regulation. Luciferase reporter assay and MTT assay demonstrated that SUMOylation of PES lcan enhance its transcriptional activation, and the promotion of cell proliferation.Our research confirmed PES1can be SUMOylated, and SUMOylation can affect the proliferation of breast cancer cells, which implied PES1might play an important role in the progression of breast cancer. So SUMOylation of PES1gives a new sight to study the pathogenesis of breast cancer.