A BIMOLECULAR MECHANISM FOR THE CELL-SIZE CONTROL OF THE CELL-CYCLE
A BIMOLECULAR MECHANISM FOR THE CELL-SIZE CONTROL OF THE CELL-CYCLE
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DOI：
10.1016/0303-2647(83)90012-6
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发表时间：
1983-01-01
期刊：
影响因子：
1.6
通讯作者：
BORTOLAN, G
中科院分区：
文献类型：
--
作者：
ALBERGHINA, L;MARTEGANI, E;BORTOLAN, G
建立了控制细胞大小的分子模型。它是以2个分子为基础的。1 (I)作为进入S期的抑制剂，在细胞分离后立即合成，每个细胞核固定数量。另一个(A)是S期的激活剂，它的合成比例与总蛋白质积累成正比。活化剂与(I)发生化学计量反应，在所有(I)分子被滴定后，(A)开始积累。当它达到一个阈值时，就会触发DNA复制的开始。该模型经仿真验证，当应用于不等分裂情况时，解释了指数增长酵母细胞群体的一些特征：TP（亲本细胞周期时间）和TD（子细胞周期时间）的长度验证了条件exp(-KTP) + exp(-KTD) = 1；不同生长速率下群体平均细胞大小的变化；父母和女儿在不同生长速率下的频率；随着系谱年龄的增加，芽形成时细胞大小增加；TP-TB周期（亲本周期时间与出芽期长度之间的差异）的存在与种群倍增时间呈线性关系。
A molecular model for the control of cell size was developed. It is based on 2 molecules. One (I) acts as an inhibitor of the entrance into S phase, and it is synthetized just after cell separation in a fixed amount per nucleus. The other (A) is an activator of the S phase, and it is synthetized at a ratio proportional to the overall protein accumulation. The activator reacts stoichiometrically with (I), and after all the (I) molecules have been titrated, (A) begins to accumulate. When it reaches a threshold value, it triggers the onset of DNA replication. This model was tested by simulation, and when applied to the case of unequal division, explains a number of features of an exponentially growing yeast cell population: the lengths of TP (cycle time of parent cells) and TD (cycle time of daughter cells) verify the condition exp(-KTP) + exp(-KTD) = 1; the changes of the average cell size of populations at different growth rates; the frequency of parents and daughters at various growth rates; the increase of cell size at bud initiation for cells of increasing genealogical age; and the existence of a TP-TB period (difference between the cycle time of parents and the length of budded phase) that depends linearly upon the doubling time of the population.