Control of cell growth and size by a novel cell cycle checkpoint mechanism

控制细胞生长和大小的机制在很大程度上是未知的，代表了一个基本的未解决的问题。 生物学上的问题。我们最近发现了一个连接有丝分裂进入和膜生长的检查点。我们 对这一检查点的分析提出了一个新的假设：我们提出，囊泡到达一个位点， 膜生长产生与膜生长程度成比例的检查点信号。我们 进一步假设下游组件读取该信号的强度以确定何时足够 发生生长以进入有丝分裂。这一假设提出了一个简单而广泛相关的解决方案， 细胞生物学中的两个基本问题：1）细胞大小如何控制？（2）膜的生长是怎样的？ 与细胞周期整合在一起提出的目标检验了假设的关键预测。目标1使用多种 方法，包括单细胞分析，以测试膜生长是否转化为成比例的 检查站信号。Aim 2测试关键检查点组件是否转换逐渐增加的检查点 将信号转换成触发有丝分裂的类似开关的输出。目标的完成将定义一个新的检查点 这是一种可以控制所有真核细胞大小和形状的机制。

The mechanisms that control cell growth and size are largely unknown and represent a fundamental unsolved problem in biology. We recently discovered a checkpoint that links mitotic entry to membrane growth. Our analysis of this checkpoint suggests a novel hypothesis: we propose that vesicles arriving at a site of membrane growth generate a checkpoint signal that is proportional to the extent of membrane growth. We further hypothesize that downstream components read the strength of this signal to determine when sufficient growth has occurred for entry into mitosis. This hypothesis suggests a simple and broadly relevant solution to two fundamental problems in cell biology: 1) How is cell size controlled? and 2) How is membrane growth integrated with the cell cycle? The proposed Aims test key predictions of the hypothesis. Aim 1 uses diverse approaches, including single cell analysis, to test whether membrane growth is translated into a proportional checkpoint signal. Aim 2 tests whether key checkpoint components translate a gradually increasing checkpoint signal into a switch-like output that triggers mitosis. Completion of the Aims will define a novel checkpoint mechanism that could control the size and shape of all eukaryotic cells.