Van Haastert P J, Jastorff B, Pinas J E, Konijn T M
J Bacteriol. 1982 Jan;149(1):99-105. doi: 10.1128/jb.149.1.99-105.1982.
Aggregative amoebae of Dictyostelium discoideum, D. mucoroides, D. purpureum, and D. rosarium react chemotactically to cyclic AMP (cAMP). We measured the chemotactic activity of 14 cAMP analogs and found that these four species have a similar sensitivity to chemical modifications of cAMP; this suggests that the cAMP receptor is identical in all of these species. Besides the induction of a chemotactic response, cAMP analogs also may delay or prevent cell aggregation. cAMP analogs like N1-O-cAMP, 2'-H-cAMP, and 5'NH-cAMP are chemotactically nearly as active as cAMP and induced no, or only a short, delay of cell aggregation. Other cAMP derivatives, such as 6-Cl-cPMP and 8-Br-cAMP, are chemotactically active only at high concentrations and delayed cell aggregation for several hours. Still other cAMP analogs, which do not induce a chemotactic reaction in D. mucoroides, D. purpureum, and D. rosarium, either prevented cell aggregation [cAMPS(S), cAMPS(R), and 3'-NH-cAMP[ or had no effect on cell aggregation [cAMPN(CH3)2(S) and cAMPN(CH3)2(R)]. cAMP analog 3'-NH-cAMP prevented cell aggregation by the inhibition of chemotaxis, whereas cell locomotion was not affected. Although we cannot provide a satisfactory explantation for these observations, our data suggest that occupation and activation of the cAMP receptors do not always induced a chemotactic response.
盘基网柄菌、黏液网柄菌、紫网柄菌和玫瑰网柄菌的聚集性变形虫对环磷酸腺苷（cAMP）产生趋化反应。我们测量了14种cAMP类似物的趋化活性，发现这四个物种对cAMP的化学修饰具有相似的敏感性；这表明在所有这些物种中cAMP受体是相同的。除了诱导趋化反应外，cAMP类似物还可能延迟或阻止细胞聚集。像N1-O-cAMP、2'-H-cAMP和5'NH-cAMP这样的cAMP类似物在趋化性上几乎与cAMP一样活跃，并且不会诱导细胞聚集延迟，或者只会有短暂的延迟。其他cAMP衍生物，如6-Cl-cPMP和8-Br-cAMP，仅在高浓度下具有趋化活性，并使细胞聚集延迟数小时。还有一些cAMP类似物，在黏液网柄菌、紫网柄菌和玫瑰网柄菌中不会诱导趋化反应，它们要么阻止细胞聚集[cAMPS(S)、cAMPS(R)和3'-NH-cAMP]，要么对细胞聚集没有影响[cAMPN(CH3)2(S)和cAMPN(CH3)2(R)]。cAMP类似物3'-NH-cAMP通过抑制趋化作用阻止细胞聚集，而细胞运动不受影响。尽管我们无法对这些观察结果给出令人满意的解释，但我们的数据表明，cAMP受体的占据和激活并不总是诱导趋化反应。
