Superinduction of the Dictyostelium discoideum cell surface cAMP receptor by pulses of cAMP.
Superinduction of the Dictyostelium discoideum cell surface cAMP receptor by pulses of cAMP.
复制标题
cAMP 脉冲对盘基网柄菌细胞表面 cAMP 受体的超诱导。
DOI：
10.1073/pnas.84.4.1030
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发表时间：
1987
影响因子：
11.1
通讯作者：
Lodish,HF
中科院分区：
文献类型：
--
作者：
Chisholm,RL;Hopkinson,S;Lodish,HF
细胞外cAMP在调节盘基网柄藻的发育程序中起着至关重要的作用，作为一种趋化剂，以及调节发育表达基因表达的信号。这些活动似乎是由cAMP的细胞表面受体介导的。我们已经研究了这种受体的调节在饥饿的悬浮培养物中开发的细胞暴露于50 nM脉冲的cAMP每6分钟。cAMP脉冲的细胞显示大约10倍的cAMP受体水平比细胞，开发的过滤器或饥饿的悬浮液中没有cAMP脉冲。基于饱和结合分析，超诱导的结合活性代表受体数量的增加，而对cAMP的受体亲和力不受影响。超诱导细胞的光亲和标记导致在饥饿细胞中标记的相同分子的特异性标记。这种增加的cAMP结合活性也在cAMP脉冲细胞的膜制备物中检测到。这些结果提供了一种不寻常的受体调节模式的证据：受体的配体的自体诱导。
Extracellular cAMP plays a crucial role in regulating the developmental program of Dictyostelium discoideum, functioning as a chemotactic agent, as well as a signal that regulates expression of developmentally expressed genes. These activities appear to be mediated by a cell-surface receptor for cAMP. We have studied the regulation of this receptor in cells developed in starved suspension cultures exposed to 50 nM pulses of cAMP every 6 min. cAMP-pulsed cells display roughly 10-fold higher cAMP receptor levels than cells that developed on filters or that were starved in suspension without cAMP pulses. Based on saturation binding analysis, the superinduced binding activity represents an increase in receptor number, while receptor affinity for cAMP is unaffected. Photoaffinity labeling of superinduced cells results in specific labeling of the same molecules that are labeled in starved cells. This increased cAMP binding activity was also detected in membrane preparations from cAMP-pulsed cells. These results provide evidence for an unusual mode of receptor regulation: autogenous induction of the receptor by its ligand.