Photoaffinity labeling of the cell surface adenosine 3':5'-monophosphate receptor of Dictyostelium discoideum and its modification in down-regulated cells.
Photoaffinity labeling of the cell surface adenosine 3':5'-monophosphate receptor of Dictyostelium discoideum and its modification in down-regulated cells.
复制标题
盘基网柄菌细胞表面腺苷 3:5-单磷酸受体的光亲和标记及其在下调细胞中的修饰。
DOI：
10.1016/s0021-9258(19)70017-9
复制
发表时间：
1981
期刊：
影响因子：
--
通讯作者：
C. Klein
中科院分区：
文献类型：
--
作者：
M. H. Juliani;C. Klein
利用光亲和类似物8-N3-[32 P]cAMP鉴定了盘基网柄藻细胞表面cAMP受体。标记的完整细胞的一个组成部分，确定由十二烷基硫酸钠-聚丙烯酰胺凝胶电泳（SDS-PAGE）和放射自显影，可以特异性地抑制非放射性cAMP的存在。在营养细胞上未发现P45（表观分子量为45，000），但随着细胞分化和表面cAMP结合位点水平的增加，其标记强度增加。发育突变体，饥饿的条件下，他们不表达显着水平的cAMP结合位点，没有纳入放射性到这种蛋白质。这些突变体在分化诱导条件下饥饿时确实标记P45，使得它们的表面cAMP结合位点水平增加。P45与从8-N3-[32 p]cAMP共价结合的细胞分离的质膜部分共纯化。下调的阿米巴原虫，显示约25%的未处理细胞的结合活性，没有标记P45。然而，这些细胞确实标记了一种表观分子量为47，000的新组分（P47）。该组分的出现代表了在这些条件下标记谱中唯一可辨别的差异。与P45的情况一样，如果在非放射性cAMP存在下进行8-N3-[32 P]cAMP的光活化，则不会发生放射性掺入P47。
The cAMP cell surface receptor of Dictyostelium discoideum amoebae was identified by the use of the photoaffinity analogue 8-N3-[32P]cAMP. Labeling by intact cells of one component, identified by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and autoradiography, could be specifically inhibited by the presence of nonradioactive cAMP. The component, P45 (apparent molecular weight of 45,000), was not identified on vegetative cells but was labeled with increasing intensity as cells differentiated and increased their levels of surface cAMP binding sites. Developmental mutants, starved under conditions where they do not express significant levels of cAMP binding sites, did not incorporate radioactivity into this protein. These mutants did label P45 when starved under differentiation-inducing conditions such that their levels of surface cAMP binding sites increased. P45 co-purified with the plasma membrane fraction isolated from cells to which 8-N3-[32p]cAMP had been covalently bound. Down-regulated amoebae, which displayed approximately 25% of the binding activity of untreated cells, did not label P45. These cells did, however, label a new component with an apparent molecular weight of 47,000 (P47).l The appearance of this component represented the only discernible difference in labeling profile under these conditions. As in the case of P45, radioactive incorporation into P47 did not occur if the photoactivation of 8-N3-[32P]cAMP was performed in the presence of nonradioactive cAMP.