Independent regulation of the extracellular cyclic AMP phosphodiesterase-inhibitor system and membrane differentiation by exogenous cyclic AMP in Dictyostelium discoideum.
Independent regulation of the extracellular cyclic AMP phosphodiesterase-inhibitor system and membrane differentiation by exogenous cyclic AMP in Dictyostelium discoideum.
复制标题
盘基网柄菌中外源环 AMP 对细胞外环 AMP 磷酸二酯酶抑制剂系统和膜分化的独立调节。
DOI：
10.1016/0012-1606(78)90245-2
复制
发表时间：
1978
影响因子：
2.7
通讯作者：
M. B. Coukell
中科院分区：
文献类型：
--
作者：
R. P. Yeh;F. Chan;M. B. Coukell
用100 nM的cAMP脉冲处理悬浮于缓冲液中的盘状网柄藻（Dictyosteeliumdiscoideum）的阿米巴细胞，细胞外cAMP磷酸二酯酶（ePD）活性显著升高，磷酸二酯酶抑制剂（PDI）的合成受到抑制。此外，接触位点A、膜结合cAMP磷酸二酯酶和cAMP结合位点在细胞表面上出现的时间加快了3-4小时，细胞内cAMP的浓度增加了20倍。当cAMP脉冲的浓度降低至InM时，脉冲对膜分化和对cAMP池的影响几乎相同，而对ePD-PDI系统的影响降低。当cAMP持续加入细胞悬液中时，核苷酸对细胞膜分化没有影响，不能刺激细胞内cAMP库，但ePD-PDI系统仍能正常调节。当发育突变体HC 112用cAMP脉冲处理时，膜分化和cAMP池的水平不受影响，而ePD-PDI系统对外源cAMP有反应。在另一个突变体，HC 53，膜分化刺激cAMP脉冲，这种反应是伴随着急剧增加的cAMP池的浓度。这些结果表明，ePD-PDI系统和膜分化的调节独立的外源性cAMP和ePD-PDI系统的调节不需要激活的腺苷酸环化酶。
When amoebae ofDictyostelium discoideum, suspended in buffer, were treated with 100 nMpulses of cAMP, the extracellular cAMP phosphodiesterase (ePD) activity increased dramatically and the synthesis of the phosphodiesterase inhibitor (PDI) was repressed. In addition, the time of appearance on the cell surface of contact sites A, membrane-bound cAMP phosphodiesterase, and cAMP binding sites was accelerated by 3–4 hr and the concentration of intracellular cAMP increased ⋍20-fold. When the concentration of the cAMP pulse was reduced to 1 nM, the effect of the pulses on membrane differentiation and on the cAMP pool was virtually the same, while the effect on the ePD-PDI system was reduced. When cAMP was added to the suspension continuously, the nucleotide had no effect on membrane differentiation and failed to stimulate the intracellular cAMP pool, however, the ePD-PDI system was regulated normally. When the developmental mutant, HC112, was treated with cAMP pulses, membrane differentiation and the level of the cAMP pool were unaffected, while the ePD-PDI system responded to the exogenous cAMP. In another mutant, HC53, membrane differentiation was stimulated by cAMP pulses and this response was accompanied by a sharp increase in the concentration of the cAMP pool. These results suggest that the ePD-PDI system and membrane differentiation are regulated independently by exogenous cAMP and that regulation of the ePD-PDI system does not require activation of the adenylyl cyclase.