Cyclic 3', 5'-AMP relay dictyostelium discoideum. V. Adaptation of the cAMP signaling response during cAMP stimulation
Cyclic 3', 5'-AMP relay dictyostelium discoideum. V. Adaptation of the cAMP signaling response during cAMP stimulation
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环状 3, 5-AMP 中继盘基网柄菌。
DOI：
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发表时间：
1980
影响因子：
7.8
通讯作者：
P. Devreotes
中科院分区：
文献类型：
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作者：
M. Dinauer;T. Steck;P. Devreotes
在盘状网柄藻中，细胞外cAMP激活腺苷酸环化酶，这导致细胞内cAMP和cAMP分泌速率的增加。对恒定cAMP刺激的信号传导响应在几分钟后通过适应机制终止。评估10（-6）或10（-7）M cAMP适应刺激的时程。我们使用灌注技术将确定的cAMP刺激物递送至[（3）H]腺苷标记的阿米巴，并监测其[（3）H]cAMP的分泌。用10（-6）或10（-7）M cAMP预处理阿莫地西泮至0.33-12分钟，然后立即给予10（-8）M至2.5 × 10（-7）M cAMP的测试刺激。随着预处理刺激持续时间的增加，对给定测试刺激的反应逐渐减弱并最终消失。在测试刺激物的集中期间。对10（-8）、5 × 10（-8）、10（-7）或2.5 × 10（-7）M cAMP的测试刺激的反应分别在约1、2.25、2.5和10 min后消失。1.5用10（-7）M cAMP刺激1 min是消除10（-8）M cAMP试验刺激的反应所必需的。我们的数据表明，适应在刺激后20 s内开始，迅速上升约2.5 min，并在约10 min后达到平台。10（-6）M cAMP预处理时的绝对上升速率比10（-7）M cAMP预处理时快。这些结果支持了一个工作假设，即表面cAMP受体的占据导致两个相反的细胞过程的变化，兴奋和适应，控制D。盘状体腺苷酸环化酶。
In dictyostelium discoideum, extracellular cAMP activates adenylate cyclase, which leads to an increase in intracellular cAMP and the rate of cAMP secretion. The signaling response to a constant cAMP stimulus is terminated after several minutes by an adaptation mechanism. The time- course of adaptation stimuli of 10(-6) or 10(-7) M cAMP was assessed. We used a perfusion technique to deliver defined cAMP stimuli to [(3)H]adenosine-labeled amoebae and monitored their secretion of [(3)H]cAMP. Amoebae were pretreated with 10(-6) or 10(-7) M cAMP to periods of 0.33-12 minutes, and then immediately given test stimuli of 10(-8) M to 2.5 x 10(-7) M cAMP. The response to a given test stimulus was progressively attenuated and finally extinguished as the duration of the pretreatment stimulus increased. During concentration of the test stimulus. The responses to test stimuli of 10(-8), 5 x 10(-8), 10(-7), or 2.5 x 10(-7) M cAMP were extinguished after approximately 1, 2.25,2.5, and 10 min, respectively. 1.5 min of stimulation with 10(-7) M cAMP was necessary to extinguish the response of a test stimulus of 10(-8) M cAMP. Our data suggest that adaptation begins within 20 s of stimulation, rises rapidly for approximately 2.5 min, and reaches a plateau after approximately 10 min. The absolute rate of rise was faster during pretreatment with 10(-6) than with 10(-7) M cAMP. These results support a working hypothesis in which the occupancy of surface cAMP receptors leads to changes in two opposing cellular processes, excitation and adaptation, that control the activity of D. discoideum adenylate cyclase.