Properties of rat melanin-concentrating hormone receptor 1 internalization
Properties of rat melanin-concentrating hormone receptor 1 internalization
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DOI：
10.1016/j.peptides.2004.03.026
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发表时间：
2004-10-01
期刊：
影响因子：
3
通讯作者：
Maruyama, K
中科院分区：
文献类型：
--
作者：
Saito, Y;Tetsuka, M;Maruyama, K
黑色素浓集激素（MCH）是一种在多种生理过程中起重要作用的神经肽。它激活两种G蛋白偶联受体（GPCR），MCH 1 R和MCH 2 R，其中MCH 1 R似乎是食物摄入的关键调节因子。通过使用稳定转染Flag标记的大鼠MCH 1 R的HEK 293 T细胞，我们研究了MCH诱导的内化途径的机制，这对于受体反应的脱敏或调节是重要的。流式细胞术定量分析表明，在第一个30分钟的MCH 1 R内化率的进展迅速，时间依赖性的方式，并部分抑制预处理与选择性蛋白激酶C（PKC）抑制剂Go 6850。显性负性β-arrestin-2（284-409）或发动蛋白I-K44 A的过表达显著阻止MCH诱导的MCH I R的内化，而显性负性β-arrestin-1-V53 D的过表达没有影响。在C-末端的Thr（317）、Ser（325）和Thr（342）处的三取代突变为Ala残基显著阻止MCH诱导的受体内化。在缺失突变体DeltaThr（342）和DeltaGlu（346）中观察到类似程度的内化预防，其在C末端尾部分别缺失11个和7个残基。我们的数据表明，MCH 1 R经历了快速MCH诱导的内化通过PKC，β-arrestin-2-和发动蛋白I依赖的途径和C-末端尾的一部分在内化过程中发挥了重要作用。(C)2004年爱思唯尔公司All rights reserved.
Melanin-concentrating hormone (MCH) is a neuropeptide that plays an important role in several physiological processes. It activates two G protein-coupled receptors (GPCRs), MCH1R and MCH2R, of which MCH1R seems to be a key regulator of food intake. By using HEK293T cells stably transfected with Flag-tagged rat MCH1R, we investigated the mechanism underlying the MCH-induced internalization pathway, which is important for the desensitization or regulation of the receptor response. Quantitative analysis by flow cytometry indicated that the rate of MCH1R internalization progressed in a rapid and time-dependent manner during the first 30 min, and was partly inhibited by pretreatment with the selective protein kinase C (PKC) inhibitor Go6850. Overexpression of dominant-negative beta-arrestin-2 (284-409) or dynamin I-K44 A significantly prevented MCH-induced internalization of MCH I R, while overexpression of dominant-negative beta-arrestin-1-V53 D had no effect. A triple-substituted mutant at Thr(317), Ser(325) and Thr(342) to Ala residue in the C-terminus significantly prevented MCH-induced receptor internalization. Similar extents of internalization prevention were noted with the deletion mutants DeltaThr(342) and DeltaGlu(346), lacking 11 and 7 residues in the C-terminal tail, respectively. Our data suggest that MCH1R undergoes rapid MCH-induced internalization through a PKC-, beta-arrestin-2- and dynamin I-dependent pathway and that a portion of the C-terminal tail plays an important role in the internalization process. (C) 2004 Elsevier Inc. All rights reserved.