| Summary: | 碩士 === 國立陽明大學 === 生物化學研究所 === 88 === p53 is a tumor suppressor gene that helps to maintain the integrity of the genome. Through the method of mRNA differential display, we have previously found two p53 inducible mouse genes, mDDA1 and mDDA3. The human homologue of mDDA3 has been found and designated hDDA3. The amino acid sequences of hDDA3 and mDDA3 contain 3 and 6 PXXP motifs respectively, and both include a putative coiled-coil region. Since PXXP motif and coiled-coil region may mediate protein-protein interactions, we utilized a yeast two-hybrid assay to screen for mDDA3-interacting proteins from mouse brain cDNA library.
Out of several mDDA3-interacting proteins, 53BP2 is of particular interest. Further yeast two-hybrid analyses have revealed that mDDA3 interacts with the C-terminus of mouse and human 53BP2 and its human homologue KIAA0771 but failed to interact with the full-length 53BP2 proteins and KIAA0771. hDDA3 can interact with both the C-terminus and full length of 53BP2 proteins and homologues. We also found that deletion of the N-terminal region containing 2 PXXP motifs of hDDA3 does not interfere with its 53BP2 binding ability.
Immunofluorescence studies revealed that hDDA3 is localized in both the cytoplasm and the nucleus. 53BP2 is present mainly in the cytoplasm but when co-expressed with hDDA3, a fraction of 53BP2 protein seems to relocate to the perinuclear region.
53BP2 has been found to stimulate the transactivation activity of p53. But utilizing a luciferase assay, hDDA3 didn't seem to affect the stimulation of p53 by 53BP2. The functional significance of 53BP2-hDDA3 interaction thus remains to be elucidated.
中文摘要……………………………………1
英文摘要……………………………………2
壹. 緒論……………………………………3
貳. 實驗材料與方法………………………11
參. 實驗結果………………………………25
肆. 討論……………………………………33
伍. 圖表……………………………………40
陸. 參考文獻………………………………57
|
|---|
