Septin1, A Human Lymphocyte Specific Expression Of Gene Function Studies

The septins are a novel family of proteins that were first recognized in yeast as proteins associated with the cell cycle control. Septins are broadly expressed throughout the animal kingdom, and yet seem to be absent from plants . Although septins were originally identified as a protein family involved in cytokinesis, recent advances in the field have now ascribed additional functions to these proteins, they are now known to have diverse cellular roles which include polarity determination, cytoskeletal reorganization, membrane dynamics, vesicle trafficking, and exocytosis. They do some important function in cell growth and mitosis.In this paper, we first identified human septin1 is a lymphocyte specially expressed protein. When septin1 is knock down in human T lymphoma cell line(Jurkat), it will lead to cell death and cell cycle arrest. These results suggest septin1 is necessary for mitosis of lymphocyte, and it will be important for lymphocyte growth and proliferation.We find septin1 can be phosphorylated by human CK2 kinase in lymphocyte. CK2 kinase can phosphorylate septin1 in 206 serinine resicue. This modify will affect septin1's function in cell cycle control directly. We also find septin1 can be interact with humanγ—Tubulin. This result suggest septin1 perhaps do its function by influencing microtubles' organization or dynamics.The special expression and important fuction make septin1 own the potential to become a target to screen out the small molecular that can be used for inhibitor of lymphocyte and lymphoma. We try to get the structure of septin1 in order to screen out the small molecular inhibitor. Using the site mutation technic, we get the mutant that can be crystallized. This septin 1 mutant was crystallized and diffraction data were collected to 2.5 A°resolution. This work lay a foundation for the research of septin's structure.