Mato J M, Konijn T M
Biochim Biophys Acta. 1975 Apr 7;385(2):173-9. doi: 10.1016/0304-4165(75)90345-1.
To obtain more information about how cyclic AMP mediates cell aggregation as found in some species of the cellular slime molds, we determined the maximal binding activity of cyclic AMP in different species under various environmental conditions. The binding of cyclic AMP is limited to amoebae using this cyclic nucleotide as chemotactic agent. Maximal binding activity proved to coincide with a maximal chemotactic response and to be related to the length of the period between the vegetative and the aggregative phase. Of the species studied, Dictyostelium discoideum has the highest cellular density of cyclic AMP receptors and is the most sensitive to cyclic AMP as attractant. At 15 degrees C, aggregation begins later, chemotaxis takes effect over a greater distance, and the maximal binding activity is higher than 22 degrees C. The number of cyclic AMP receptors is independent of temperature. The delay in the onset of aggregation and the increased chemotactic response in darkness is not due to a change in the maximal binding activity. The binding of cyclic AMP and its inactivation is discussed in the light of cell aggregation.
为了获取更多关于环磷酸腺苷（cAMP）如何介导细胞聚集的信息，就像在某些黏菌细胞物种中所发现的那样，我们测定了在不同环境条件下不同物种中环磷酸腺苷的最大结合活性。环磷酸腺苷的结合仅限于将这种环核苷酸用作趋化剂的变形虫。最大结合活性被证明与最大趋化反应一致，并且与营养期和聚集期之间的时间长度有关。在所研究的物种中，盘基网柄菌具有最高的环磷酸腺苷受体细胞密度，并且对作为引诱剂的环磷酸腺苷最为敏感。在15摄氏度时，聚集开始得较晚，趋化作用在更大的距离上起作用，并且最大结合活性高于22摄氏度。环磷酸腺苷受体的数量与温度无关。聚集开始的延迟以及在黑暗中趋化反应的增强并非由于最大结合活性的变化。结合细胞聚集来讨论环磷酸腺苷的结合及其失活。
