Characterization and developmental patterns of telomerase expression in plants
Characterization and developmental patterns of telomerase expression in plants
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DOI：
10.1073/pnas.93.25.14422
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发表时间：
1996-12-10
影响因子：
11.1
通讯作者：
Shippen, DE
中科院分区：
文献类型：
--
作者：
Fitzgerald, MS;McKnight, TD;Shippen, DE
端粒酶活性在哺乳动物中受到发育调节。在这里，我们研究端粒酶活性的植物，其发展的根本方式不同于动物。使用修改后的版本的端粒重复扩增协议（TRAP）测定，我们检测到的活性提取物从胡萝卜，花椰菜，大豆，拟南芥，水稻与预期的所有特征的端粒酶合成植物端粒重复序列TTTAGGG。该活性依赖于RNA和蛋白质组分，需要dGTP、dATP和dTTP，但不需要dCTP，并产生具有7个核苷酸周期的产物。端粒酶活性是丰富的花椰菜分生组织和未分化的细胞从拟南芥，大豆，胡萝卜悬浮培养，但低或检测不到从成熟植物分化组织的取样。花椰菜分生组织中的端粒酶对DNA序列要求较低，这可能反映了Fire在断裂染色体上形成端粒的能力。端粒酶表达的显著差异及其与细胞增殖能力的相关性反映了分化和永生化过程中端粒酶水平的变化，因此，端粒酶活化似乎是涉及赋予长期增殖能力的保守机制。
Telomerase activity is developmentally regulated in mammals. Here we examine telomerase activity in plants, whose development differs in fundamental ways from that of animals. Using a modified version of the telomere repeat amplification protocol (TRAP) assay, we detected an activity in extracts from carrots, cauliflower, soybean, Arabidopsis, and rice with all the characteristics expected for a telomerase synthesizing the plant telomere repeat sequence TTTAGGG. The activity was dependent on RNA and protein components, required dGTP, dATP, and dTTP, but not dCTP, and generated products with a seven nucleotide periodicity. Telomerase activity was abundant in cauliflower meristematic tissue and undifferentiated cells from Arabidopsis, soybean, and carrot suspension cultures, but was low or not detectable in a sampling of differentiated tissues from mature plants. Telomerase from cauliflower meristematic tissues exhibited relaxed DNA sequence requirements, which might reflect the capacity to form telomeres on broken chromosomes in Fire, The dramatic differences in telomerase expression and their correlation with cellular proliferation capacity mirror changes in human telomerase levels during differentiation and immortalization, Hence, telomerase activation appears to be a conserved mechanism involved in conferring long-term proliferation capacity.