Importance of the carboxy-terminus of the CXCR2 for signal transduction.
Importance of the carboxy-terminus of the CXCR2 for signal transduction.
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CXCR2 羧基末端对于信号转导的重要性。
DOI：
10.1006/bbrc.1998.8246
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发表时间：
1998
期刊：
影响因子：
--
通讯作者：
Takamori,H
中科院分区：
文献类型：
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作者：
Schraufstatter,IU;Burger,M;Hoch,RC;Oades,ZG;Takamori,H
加入IL-8或MGSA后15秒内，CXCR 2在C-末端胞质内部分磷酸化。用缺失最后12个氨基酸（T3）的截短形式的受体转染的细胞显示出正常的结合亲和力，但不再磷酸化;单个丙氨酸置换表明Ser 346和348是磷酸化的主要位点。在研究磷酸化在CXCR 2脱敏中的重要性时，表达野生型CXCR 2的细胞在第一次暴露于IL-8后失去了高于基础速率的GTPγS结合，而具有T3突变体的细胞在第二次暴露于IL-8后保留了60%的诱导GTPγS交换的能力。相反，受体内化不受T3突变体磷酸化丧失的影响。进一步的受体截短导致IL-8和MGSA的结合亲和力降低，加入过量配体后GTPγS交换速率降低，这表明该区域参与G蛋白偶联。
The CXCR2 is phosphorylated at the C-terminal intracytoplasmic portion within 15 sec following the addition of IL-8 or MGSA. Cells transfected with a truncated form of the receptor missing the last 12 amino acids (T3) showed normal binding affinity, but were no longer phosphorylated; individual alanine replacement indicated that Ser346 and 348 were the primary sites of phosphorylation. In studies of the importance of phosphorylation in CXCR2 desensitization, cells expressing wild type CXCR2 lost GTPγS binding above basal rate after the first exposure to IL-8, while cells with the T3 mutant retained 60% of their capacity to induce GTPγS exchange upon a second exposure to IL-8. In contrast, receptor internalization was not affected by the loss of phosphorylation of the T3 mutant. Further receptor truncation led to decreasing binding affinities for IL-8 and MGSA and a decreased rate of GTPγS exchange following addition of excess ligand which suggests involvement of this region in G-protein coupling.