RUI: Induction of Cell Division by Protein Kinase C

小行星9220108 当发现佛波醇酯能诱导非洲爪蟾卵母细胞减数分裂时，提出了一条诱导减数分裂的新途径。 已知磷酸盐通过蛋白激酶C起作用，但蛋白激酶C以外的细胞分裂途径尚不清楚。 蛋白激酶C也被认为参与rasp 21、胰岛素、胰岛素样生长因子-1（IGF-1）和一些其他生长因子的增殖途径。 由于phorectin，ras p21，胰岛素和IGF-1启动非洲爪蟾卵母细胞减数分裂细胞分裂，我们将研究是否PKC通过调节一个或多个四个不同的细胞周期调控蛋白的行为。 在体内和体外研究中，ras p21、mos、细胞周期蛋白和p34 cdc 2的磷酸化、数量和活性将作为蛋白激酶C活性的函数进行检查。 可以发现，只有一种同工酶形式的PKC对增殖的调节是重要的，并且PKC通过调节特定的蛋白质来诱导细胞分裂。 这项研究应该阐明迄今为止在细胞分裂途径中没有特征的步骤。 某些植物产品，佛波醇酯，诱导动物细胞的细胞分裂。 这些化学物质激活一种称为蛋白激酶C（PKC）的酶。 蛋白激酶C的功能是将 其他蛋白质上的磷酸基团。 许多证据表明，生长激素如胰岛素、胰岛素样生长因子1和表皮生长因子通过激活蛋白激酶C诱导细胞分裂。 除了蛋白激酶C的激活以外，导致细胞分裂的步骤尚不清楚。 在过去的五年里，另一个独立的研究方向是寻找对细胞分裂重要的基因和蛋白质。 一些新发现的蛋白质被称为mos，细胞周期蛋白，p34 cdc 2和ras p21。 本研究的目的是：（a）确定蛋白激酶C是否可以在试管或活细胞中将磷酸盐转移到这些蛋白质上，（B）如果不能，则定位磷酸盐添加到这些蛋白质上的位点，以及（c）确定这些重要的细胞分裂蛋白质是否通过磷酸盐的添加而打开或关闭。 这项研究的结果应该定义新的步骤，在一系列的事件，导致诱导细胞分裂的生长因子。 由于这项研究将在本科院校进行，并有学生参与，它也将有助于培养下一代科学家。 ***

9220108 Stith A new pathway for the induction of meiotic cell division was suggested when a phorbol ester was found to induce meiosis in Xenopus oocytes. It is known that phorbols act through protein kinase C, but the pathway to cell division beyond protein kinase C is not known. Protein kinase C is also believed to be involved in the proliferative pathway of ras p21, insulin, insulin-like growth factor-1 (IGF-1) and some other growth factors. Since phorbols, ras p21, insulin and IGF-1 initiate meiotic cell division in Xenopus laevis oocytes, we will examine whether PKC acts through regulation of one or more of four different cell cycle regulatory proteins. With both in vivo and in vitro studies, the phosphorylation, amount and activity of ras p21, mos, cyclin, and p34cdc2 will be examined as a function of protein kinase C activity. It may be found that only one isozymic form of PKC is central to the regulation of proliferation and that PKC induces cell division through regulation of specific protein(s). This research should elucidate heretofore uncharacterized steps in the pathway to cell division. %%% Certain plant products, phorbol esters, induce cell division in animal cells. These chemicals activate an enzyme known as protein kinase C (PKC). The function of protein kinase C is to transfer phosphate groups onto other proteins. Much evidence suggests that growth hormones such as insulin, insulin-like growth factor 1 and epidermal growth factor induce cell division by activating protein kinase C. The steps beyond activation of protein kinase C which lead to cell division are not known. A separate line of research over the past five years has been the search for genes and proteins important to cell division. Some of the newly discovered proteins are called mos, cyclin, p34cdc2 and ras p21. The goals of this research are: (a) to determine whether protein kinase C can transfer phosphate to these proteins in a test tube or in living cells, (b) if i t does, to locate the site of phosphate addition to these proteins, and (c) determine whether these important cell division proteins are turned on or off by the addition of phosphate. The results of this research should define new steps in the sequence of events that leads to induction of cell division by growth factors. Since this research will be carried out at an undergraduate institution with the participation of students, it will also contribute to training a future generation of scientists. ***