The glucocorticoid domain: Steroid-mediated changes in the rate of synthesis of rat hepatoma proteins
The glucocorticoid domain: Steroid-mediated changes in the rate of synthesis of rat hepatoma proteins
复制标题
糖皮质激素结构域：类固醇介导的大鼠肝癌蛋白合成率的变化
DOI：
10.1016/0092-8674(78)90136-8
复制
发表时间：
1978
期刊：
影响因子：
64.5
通讯作者：
P. O’Farrell
中科院分区：
文献类型：
--
作者：
R. Ivarie;P. O’Farrell
Changes in the rate of synthesis of rat hepatoma proteins in response to the synthetic glucocorticoid, dexamethasone, have been measured by two-dimensional gel electrophoresis(O’Farrell, 1975a). In the most extensively analyzed cell line (HTC cells), two classes of steroid-responsive gene products are found: seven Class I proteins, which are induced essentially every time they are detected on two-dimensional gel autoradiograms, and about sixteen Class II proteins, which are induced and/or repressed infrequently even though they are detected in almost every experiment. Contained in Class I is the steroidinducible enzyme tyrosine aminotransferase as identified by its specific immunoprecipitation with antiTAT serum. Also in Class I are two series of proteins, termed Belts I and II, which are tentatively deduced to be sialoglycoproteins from their electrophoretic properties in this gel system. Belt I is localized on the HTC cell surface as shown by its labeling following radioiodination of whole cells. Class I polypeptides respond quite uniformly to dexamethasone in that they were induced with the same apparent kinetics and their induction ratios fell in the range of 3-10. The number of Class I proteins,~ 1% of the observed proteins, provides a quantitative measure of the specificity of the observed dexamethasone response.Class II proteins behave as if their hormonal sensitivity varied between experiments. All proteins having decreased rates of synthesis after administration of dexamethasone fall into Class II. Their repression ratios are small, never exceeding 3, and only one (rI) repressed with any consistency(9 of 16 experiments). In three experiments with another rat hepatoma line (FAZA cells), eight proteins were induced by the steroid and one repressed in all three experiments. Except for tyrosine aminotransferase, the inducible gene products from FAZA cells were electrophoretically different from the HTC set. Two of the inducible proteins in FAZA cells, however, were detectable in HTC cells: one was unaffected by dexamethasone in HTC cells and the other (rI) repressed quite frequently. Thus
