REPRESSION OF GROWTH-REGULATED G1 CYCLIN EXPRESSION BY CYCLIC-AMP IN BUDDING YEAST
REPRESSION OF GROWTH-REGULATED G1 CYCLIN EXPRESSION BY CYCLIC-AMP IN BUDDING YEAST
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DOI：
10.1038/371339a0
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发表时间：
1994-09-22
期刊：
影响因子：
64.8
通讯作者：
ALBERGHINA, L
中科院分区：
文献类型：
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作者：
BARONI, MD;MONTI, P;ALBERGHINA, L
酵母细胞成为致力于细胞分裂周期，只有当它生长到一个临界尺寸（1-4），并达到蛋白质合成的临界速率（5，6）。生长和分裂之间的协调发生在细胞周期G1期的控制步骤，称为启动（4）。它依赖于由CLN 1、2和3编码的G1特异性细胞周期蛋白，其通过Cdc 28蛋白激酶的激活触发Start。事实上，Cln循环是Start执行的速率限制，并取决于增长。在这里，我们报道了cAMP信号通路（11）调节Cln细胞周期蛋白对生长的依赖性。特别是，需要更多的生长来触发Start，因为CLN 1和CLN 2被cAMP信号抑制，从而解释了先前观察到的蛋白质合成的临界大小和临界速率的cAMP依赖性增加（12）。Cln 3不受cAMP途径的抑制，并通过部分介导其他G1细胞周期蛋白的生长依赖性表达来抵消这种机制。
YEAST cell becomes committed to the cell division cycle only if it grows to a critical size(1-4) and reaches a critical rate of protein synthesis(5,6). The coordination between growth and division takes place at a control step during the G1 phase of the cell cycle called Start(4). It relies on the G1-specific cyclins encoded by CLN1, 2 and 3, which trigger Start through the activation of the Cdc28 protein kinase. In fact, the Cln cyclins are rate-limiting for Start execution and depend on growth. Here we report that the cyclic AMP signal pathway(11) modulates the dependency of Cln cyclins on growth. In particular, more growth is required to trigger Start because CLN1 and CLN2 are repressed by the cAMP signal, thus explaining the previously observed cAMP-dependent increase of the critical size and critical rate of protein synthesis(12). Cln3 is not inhibited by the cAMP pathway and counteracts this mechanism by partially mediating the growth-dependent expression of other G1 cyclins.