Phosphorylation of chemoattractant receptors is not essential for chemotaxis or termination of G-protein-mediated responses
Phosphorylation of chemoattractant receptors is not essential for chemotaxis or termination of G-protein-mediated responses
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DOI：
10.1074/jbc.272.43.27313
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发表时间：
1997-10-24
影响因子：
4.8
通讯作者：
Hereld, D
中科院分区：
文献类型：
--
作者：
Kim, JY;Soede, RDM;Hereld, D
在一些g蛋白偶联信号系统中，配体诱导的特定激酶的受体磷酸化被认为通过受体/ g蛋白解偶联、受体内化和受体下调等机制导致脱敏。我们在这里报道，消除Dictyostelium的化学引诱剂受体的磷酸化，无论是通过丝氨酸的位点定向取代还是通过c端细胞质结构域的截断，完全阻止了激动剂诱导的配体结合丧失，但并不损害几种受体介导的反应的适应性，包括腺苷酸和鸟苷酸环化酶的激活和肌动蛋白聚合。磷酸化缺陷受体能够介导趋化、聚集和分化。我们提出，对于化学引诱剂受体，激动剂诱导的磷酸化调节表面结合活性，但其他磷酸化无关的机制介导反应适应。
In several G-protein-coupled signaling systems, ligand-induced receptor phosphorylation by specific kinases is suggested to lead to desensitization via mechanisms including receptor/G-protein uncoupling, receptor internalization, and receptor down-regulation. We report here that elimination of phosphorylation of a chemoattractant receptor of Dictyostelium, either by site-directed substitution of the serines or by truncation of the C-terminal cytoplasmic domain, completely prevented agonist-induced loss of ligand binding but did not impair the adaptation of several receptor-mediated responses including the activation of adenylyl and guanylyl cyclases and actin polymerization, In addition, the phosphorylation deficient receptors were capable of mediating chemotaxis, aggregation, and differentiation. We propose that for chemoattractant receptors agonist-induced phosphorylation regulates surface binding activity but other phosphorylation-independent mechanisms mediate response adaptation.