To ensure that extracellular stimuli are translated into intracellular signals of appropriate magnitude and specificity, most signaling cascades are tightly regulated. One of the major mechanisms involved in the regulation of G protein-coupled receptors (GPCRs) involves their endocytic trafficking. GPCR endocytic trafficking entails the targeting of receptors to discrete endocytic sites at the plasma membrane, followed by receptor internalization and intracellular sorting. This regulates the level of cell surface receptors, the sorting of receptors to degradative or recycling pathways, and in some cases the specific signaling pathways. In this chapter we discuss the mechanisms that regulate receptor endocytic trafficking, emphasizing the role of GPCR kinases (GRKs) and arrestins in this process.

中文翻译：

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GRK和抑制蛋白调节受体运输。

为了确保将细胞外刺激物翻译成适当大小和特异性的细胞内信号，大多数信号级联均受到严格调节。参与调节G蛋白偶联受体（GPCR）的主要机制之一涉及其内吞运输。GPCR内吞运输需要将受体靶向质膜上的离散内吞位点，然后进行受体内化和细胞内分选。这调节细胞表面受体的水平，受体对降解或再循环途径的分类，以及在某些情况下的特定信号传导途径。在本章中，我们讨论了调节受体内吞运输的机制，强调了GPCR激酶（GRK）和抑制蛋白在此过程中的作用。