Type IPDZ ligands are sufficient to promote rapid recycling of G protein-coupled receptors independent of binding to N-ethylmaleimide-sensitive factor
Type IPDZ ligands are sufficient to promote rapid recycling of G protein-coupled receptors independent of binding to N-ethylmaleimide-sensitive factor
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DOI：
10.1074/jbc.m406934200
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发表时间：
2005-02-04
影响因子：
4.8
通讯作者：
von Zastrow, M
中科院分区：
文献类型：
--
作者：
Gage, RM;Matveeva, EA;von Zastrow, M
G 蛋白偶联受体 (GPCR) 在不同循环和溶酶体途径之间的分子分选决定了激动剂诱导的内吞作用的功能后果。 β(2) 肾上腺素能受体 (β(2) AR) 的羧基末端胞质结构域介导 PDZ 与 50 kDa (NHERF/EBP50) 家族蛋白的 Na+/H+ 交换调节因子/ezrin/radixin/moesin 结合磷蛋白的结合以及非 PDZ 与 N-乙基马来酰亚胺敏感因子 (NSF) 的结合。我们研究了 PDZ 相互作用是否实际上足以促进内吞受体的快速回收，如果是的话，PDZ 介导的分选是否仅限于 B(2)AR 尾部或结合 NHERF/EBP50 的序列。使用嵌合突变受体检查了 PDZ 和 NSF 结合特性不同的短（10 个残基）序列的运输效应。 B(2)AR 衍生尾部序列的再循环活性不会被选择性破坏与 NSF 结合的点突变所阻断，并且鉴定出天然存在的 PDZ 配体序列，该序列不会与 NSF 可检测地结合，但仍可充当强再循环信号。 β(1)-肾上腺素能受体的羧基末端胞质结构域不与 NSF 或 NHERF/EBP50 结合，并选择性地与一组不同的 PDZ 蛋白相互作用，促进嵌合突变受体的快速回收，其效率与 β(2)AR 尾部的效率相似。这些结果表明 PDZ 结构域介导的蛋白质相互作用足以促进 GPCR 的快速回收，而与 NSF 的结合无关。他们还表明，PDZ 定向回收是一种相当通用的 GPCR 调节机制，不仅限于单个 GPCR，并且可能涉及除 NHERF/EBP50 之外的其他含有 PDZ 结构域的蛋白质。
Molecular sorting of G protein-coupled receptors (GPCRs) between divergent recycling and lysosomal pathways determines the functional consequences of agonist-induced endocytosis. The carboxyl-terminal cytoplasmic domain of the beta(2) adrenergic receptor (beta(2)AR) mediates both PDZ binding to Na+/H+ exchanger regulatory factor/ezrin/radixin/moesin-binding phosphoprotein of 50 kDa (NHERF/EBP50) family proteins and non-PDZ binding to the N-ethylmaleimide-sensitive factor (NSF). We have investigated whether PDZ interaction(s) are actually sufficient to promote rapid recycling of endocytosed receptors and, if so, whether PDZ-mediated sorting is restricted to the B(2)AR tail or to sequences that bind NHERF/EBP50. The trafficking effects of short (10 residue) sequences differing in PDZ and NSF binding properties were examined using chimeric mutant receptors. The recycling activity of the B(2)AR-derived tail sequence was not blocked by a point mutation that selectively disrupts binding to NSF, and naturally occurring PDZ ligand sequences were identified that do not bind detectably to NSF yet function as strong recycling signals. The carboxyl-terminal cytoplasmic domain of the beta(1)-adrenergic receptor, which does not bind either to NSF or NHERF/EBP50 and interacts selectively with a distinct group of PDZ proteins, promoted rapid recycling of chimeric mutant receptors with efficiency similarly high as that of the beta(2)AR tail. These results indicate that PDZ domain-mediated protein interactions are sufficient to promote rapid recycling of GPCRs, independent of binding to NSF. They also suggest that PDZ-directed recycling is a rather general mechanism of GPCR regulation, which is not restricted to a single GPCR, and may involve additional PDZ domain-containing protein(s) besides NHERF/EBP50.