MECHANISM OF TRANSFORMATION BY TYROSINE KINASES

我们的最终目标仍然是确定癌变的机制。 酪氨酸特异性蛋白激酶的转化。我们在这里提议 进一步测试我们的假设，通过改变酪氨酸磷酸化 细胞酪氨酸激酶在锚定非依赖性生长中的作用 已转换单元的属性。我们已经观察到一个被膜包裹的 水疱性口炎病毒(VSV)选择性地获得特异性 来自锚定非依赖细胞的酪氨酸激酶。因此，我们将 VSV相关酪氨酸酶的纯化及免疫学试剂的制备 用于研究该酶在体内的位置和数量的激酶 锚定独立细胞。来检验酪氨酸氨基转移酶 VSV获得的激酶在锚定独立性中发挥作用，它将是 确定VSV获得的酶是否与酪氨酸酶相同 一种先前已被证明可导致锚定独立性的激酶 一些转化的细胞。 为了确定特定底物蛋白的酪氨酸磷酸化如何 可能受到调控，我们将测试细胞酪氨酸激酶物种是否 活性扩增或在去角质细胞中重新定位。这 将通过高效液相色谱凝胶过滤个别种类的酪氨酸激酶和 对它们的活动和亚细胞位置进行量化。我们的 初步数据表明，另一种监管机制是通过 前列腺酸性磷酸酶对磷酸酪氨酸的脱磷作用。这 将在人前列腺癌细胞中测试调节模式 前列腺酸性磷酸酶活性可受雄激素调节。 开始了解蛋白质的酪氨酸磷酸化是如何导致 细胞的恶性生长，我们将研究一类新的酪氨酸 我们在人细胞外组分中鉴定的激酶底物 前列腺癌细胞。我们会确定这些是不是秘密的 蛋白质和制备免疫试剂以用于其进一步的 人物刻画。

Our ultimate goal remains to determine the mechanism of meoplastic transformation by tyrosine-specific protein kinases. We propose here to further test our hypothesis that altered tyrosine phosphorylation by cellular tyrosyl kinases functions in the anchorage independent growth property of transformed cells. We have observed that a membrane-enveloped virus, vesicular stomatitis virus (VSV), selectively acquires specific tyrosyl kinase species from anchorage independent cells. We will therefore purify and prepare immunological reagents to the VSV-associated tyrosyl kinase to be used to investigate location and amount of this enzyme in anchorage independent cells. To test the hypothesis that the tyrosyl kinase acquired by VSV functions in anchorage independence, it will be determined whether the VSV-acquired enzyme is the same as the tyrosyl kinase which has previously been shown to cause anchorage independence in some transformed cells. To determine how tyrosine-phosphorylation of specific substrate proteins may be regulated, we will test whether cellular tyrosyl kinase species are amplified in activity or relocalized in achorage independent cells. This will be by HPLC gel filtration of individual species of tyrosyl kinases and quantitations of their activities and subcellular locations. Our preliminary data suggests that another mechanism for regulation is by dephosphorylation of phosphotyrosine by prostatic acid phosphatase. This mode of regulation will be tested in human prostate carcinoma cells where prostatic acid phosphatase activity can be regulated by androgens. To begin to understand how tyrosine phosphorylation of proteins may cause malignant growth of cells, we will investigate a new class of tyrosyl kinase substrates identified by us in the extracellular fraction of human prostate carcinoma cells. We will determine whether these are secreted proteins and prepare immunological reagents to be used in their further characterization.