The Gene Function Study Of Specificity Phosphatase PPM1A

Cell cycle is a continuous process in which one cell divides into two identical daughter cells. In order to ensure the accuracy of duplication, the cell evolved supervision mechanisms which are called cell cycle check points.A series of accurate and timely phosphorylation and dephosphorylation reactions are the core events of normal division process of mitosis. From the molecular mechanism of spindle checkpoint and the major components of SAC, we could know that the involvement of protein kinases is very necessary. For example, the Mpsl protein kinase is an impotant component of the spindle checkpoint, its phosphorylation status decides the association or dissociation between Mps1 protein and the centromere. Correspondant with the existence of phosphorylation, dephosphorylation also plays an important role in the cell cycle regulation. Protein phosphatase plays a reverse role through taking off the phosphate groups. Through our previous study we found that the specific phosphatase of Mpsl kinase are PPM1A and PPM1B.PPM1A protein is a common protein phosphatase, a member of PPM family. It is involved in many important signal pathways through dephosphorylation. The studies concerning the dephosphorylation of Mpsl could provide a better understanding about the regulation of cell cycle and a new way of treatment for the tumor. The fact that PPM1A is very likely to be the enzyme that controls the phosphorylation status of Mpsl is confirmed by the cell transfection experiments. To explore PPM1A's function in intact animals we constructed the gene knockout animal model. We used mice as model organism; constructed the conditional gene targeting vector; transfected it to the embryonic stem (ES) cells; screened the clones whose genes had been correctly targeted; finally we got the chimeric mouse. Our work set up the foundation of follow-up analysis and research on PPM1A gene functions.