期刊
JOURNAL OF BIOLOGICAL CHEMISTRY
卷 276, 期 25, 页码 22772-22778出版社
AMER SOC BIOCHEMISTRY MOLECULAR BIOLOGY INC
DOI: 10.1074/jbc.M101756200
关键词
-
Cellular dedifferentiation is the major process underlying totipotency, regeneration, and formation of new stem cell lineages in multicellular organisms, In animals it is often associated with carcinogenesis. Here, we used tobacco protoplasts (plant cells devoid of cell wall) to study changes in chromatin structure in the course of dedifferentiation of mesophyll cells. Using flow cytometry and micrococcal nuclease analyses, we identified two phases of chromatin decondensation prior to entry of cells into S phase. The first phase takes place in the course of protoplast isolation, following treatment with cell wall degrading enzymes, whereas the second occurs only after protoplasts are induced with phytohormones to re-enter the;cell cycle. In the absence of hormonal application, protoplasts undergo cycles of chromatin condensation/decondensation and die. The ubiquitin proteolytic system was found indispensable for protoplast progression into S phase, being required for the second but not the first phase of chromatin decondensation, The emerging model suggests that cellular dedifferentiation proceeds by two functionally distinct phases of chromatin decondensation: the first is a transitory phase that confers competence for cell fate switch, which is followed, under appropriate conditions, by a second proteasome dependent phase representing a commitment for the mitotic cycle. These findings might have implications for a wide range of dedifferentiation driven cellular processes in higher eukaryotes.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据