Fission yeast Tor2 promotes cell growth and represses cell differentiation
Fission yeast Tor2 promotes cell growth and represses cell differentiation
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DOI：
10.1242/jcs.03241
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发表时间：
2006-11-01
影响因子：
4
通讯作者：
Moreno, Sergio
中科院分区：
文献类型：
--
作者：
Alvarez, Beatriz;Moreno, Sergio
裂殖酵母是研究细胞生长与分化协调性的理想模型系统。在营养物质存在的情况下，分裂酵母细胞生长和分裂;在缺乏营养物质的情况下，它们停止生长并进行细胞分化。这种反应的分子机制尚未完全了解。在这里，我们证明了TOR 2，TOR蛋白激酶家族的裂变酵母成员，是控制细胞生长和细胞分化之间的开关，以响应营养供应的核心。Tor 2通过调节核糖体蛋白基因的表达来控制细胞生长和核糖体生物合成。我们已经发现Tor 2在抑制性分化方面具有额外的功能。Tor 2过表达强烈抑制交配，减数分裂和孢子形成效率，而Tor 2失活具有相反的效果，导致细胞分化，无论营养条件如何。Tor 2的这一新发现的功能似乎是通过干扰转录因子Ste 11和减数分裂促进RNA结合蛋白Mei 2的功能来发挥作用的。因此，我们的数据揭示了Tor通路的独特调节功能-确保生长和细胞分化相互排斥，并且它们之间的选择取决于环境条件。
The fission yeast Schizosaccharomyces pombe is an excellent model system in which to study the coordination of cell growth and cell differentiation. In the presence of nutrients, fission yeast cells grow and divide; in the absence of nutrients, they stop growing and undergo cell differentiation. The molecular mechanisms underlying this response are not fully understood. Here, we demonstrate that Tor2, a fission yeast member of the TOR protein kinase family, is central to controlling the switch between cell growth and cell differentiation in response to nutrient availability. Tor2 controls cell growth and ribosome biogenesis by regulating ribosomal protein gene expression. We have found that Tor2 has an additional function in repressing sexual differentiation. Tor2 overexpression strongly represses mating, meiosis and sporulation efficiency, whereas Tor2 inactivation has the opposite effect, leading to cell differentiation, regardless of the nutritional conditions. This newly revealed function of Tor2 appears to operate by interfering with the functions of the transcription factor Ste11 and the meiosis-promoting RNA-binding protein Mei2. Thus, our data reveal a unique regulatory function of the Tor pathway - ensuring that growth and cell differentiation become mutually exclusive and that the choice between them depends on environmental conditions.