| Summary: | 碩士 === 國立陽明大學 === 生化暨分子生物研究所 === 95 === Tbx2 is a member of T-box transcription factor gene family. Mice lacking Tbx2 die around E14 with cardiac defects in septation and remodeling of the outflow tract and aortic arch arteries. To further elucidate the functional roles of Tbx2 during heart development, yeast two-hybrid system was used to identify the interacting proteins. Coronin 1B, an actin binding protein involved in modulating actin dynamics, was found to interact with Tbx2. The interaction of Tbx2 and Coronin 1B was further confirmed by immuno-precipitation experiment. To get insight into the interaction of Tbx2 and Coronin1B in vivo, the expression profiles of Tbx2 and Coronin 1B in NIH3T3 mouse fibroblast cells and the embryonic hearts were examined. In NIH3T3 mouse cell line, while we found that Tbx2 is predominantly detected in the nucleus and Coronin1B is localized at cytoplasm, nuclear Coronin 1B was detected albeit the expression level is low. Tbx2 expresses in the outflow tract, inner curvature, atrioventricular canal and inflow tract, while Coronin 1B is specific localized at the endocardial cushion, endocardium and epicardium in developing heart. The endocardial cushion region is crucial for cardiac septation and valve formation. The co-expression of Tbx2 and Coronin 1B in the embryonic endocardial cushion suggests the interaction between these two proteins may play important roles in the septal division of the heart chamber and the formation of the valves. To further evaluate whether the interaction between Tbx2 and Coronin 1B affects the biological function of Tbx2, Tbx2 targeted cardiac-specific promoters, including ANF, N-Myc, Cx40 and Cx43 were constructed and luciferase based reporter assay is now under investigation.
|
|---|
