Van Haastert P J, De Wit R J, Van Lookeren Campagne M M
Biochem Biophys Res Commun. 1985 Apr 16;128(1):185-92. doi: 10.1016/0006-291x(85)91662-6.
D. discoideum cells contain surface receptors for the chemoattractant cAMP which are composed of fast and slowly dissociating binding sites with half-lifes of respectively about 1 s and 15 s (Van Haastert and De Wit, J. Biol. Chem. 259, 13321-13328). In membranes prepared by shearing the cells through a Nucleopore filter, ATP has no effect on cAMP-binding at equilibrium, but the number of slowly dissociating sites is increased about 2-fold by ATP while their apparent affinity and off-rate are not altered by ATP. The effect of ATP is stimulated about 3-fold by Ca2+ with a half maximal effect at 100 microM Ca2+. The tumor promoting phorbol ester, phorbol 12-myristate 13-acetate (PMA), increases this Ca2+-sensitivity of the ATP effect to about 0.2 microM Ca2+. These data suggest that a specific subpopulation of cAMP receptors in membranes from D. discoideum is altered by the action of protein kinase C.
盘基网柄菌细胞含有趋化因子cAMP的表面受体，这些受体由快速和缓慢解离的结合位点组成，半衰期分别约为1秒和15秒（范·哈斯特特和德·威特，《生物化学杂志》259，13321 - 13328）。在通过核孔滤膜剪切细胞制备的膜中，ATP在平衡时对cAMP结合没有影响，但ATP使缓慢解离位点的数量增加约2倍，而其表观亲和力和解离速率不受ATP影响。Ca2 +可使ATP的作用增强约3倍，在100微摩尔Ca2 +时达到最大效应的一半。促肿瘤佛波酯，佛波醇12 - 肉豆蔻酸酯13 - 乙酸酯（PMA），将ATP效应的这种Ca2 +敏感性提高到约0.2微摩尔Ca2 +。这些数据表明，盘基网柄菌膜中cAMP受体的一个特定亚群因蛋白激酶C的作用而发生改变。
