A basic peptide within the juxtamembrane region is required for EGF receptor dimerization
A basic peptide within the juxtamembrane region is required for EGF receptor dimerization
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DOI：
10.1016/j.yexcr.2004.08.032
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发表时间：
2005-01-01
影响因子：
3.7
通讯作者：
Hermanson, O
中科院分区：
文献类型：
--
作者：
Aifa, S;Aydin, J;Hermanson, O
表皮生长因子受体（EGFR）是正常细胞生长和器官发育的基础，但也涉及各种病理，特别是上皮来源的肿瘤。我们先前已经证明，细胞内EGFR膜区域（R-645-R-657）内的起始13个氨基酸（P13）参与了与钙调蛋白的相互作用，从而表明该区域在EGFR功能中的重要作用。我们在表达内源性EGFR的COS-7细胞中表达EGFR的胞内结构域（TKJM）或缺乏P13的胞内结构域（DeltaTKJM）。只有TKJM与针对EGFR细胞外部分的抗体免疫沉淀，并且只有TKJM被内源性EGFR酪氨酸磷酸化。使用不表达内源性EGFR的SK-N-MC细胞，其用野生型EGFR或缺乏P13的重组全长EGFR稳定转染，证明P13是适当受体二聚化所需的。此外，缺乏P13的突变型EGFR不能被自磷酸化。P13富含碱性氨基酸，结合我们的研究结果，EGFR的计算机模拟表明EGFR的胞膜结构域（JM）在介导细胞内二聚化中具有新的作用，从而介导受体激酶的活化和功能。(C)2004年爱思唯尔公司All rights reserved.
The epidermal growth factor receptor (EGFR) is fundamental for normal cell growth and organ development, but has also been implicated in various pathologies, notably tumors of epithelial origin. We have previously shown that the initial 13 amino acids (P13) within the intracellular juxtamembrane region (R-645-R-657) are involved in the interaction with calmodulin, thus indicating an important role for this region in EGFR function.Here we show that P13 is required for proper dimerization of the receptor. We expressed either the intracellular domain of EGFR (TKJM) or the intracellular domain lacking P13 (DeltaTKJM) in COS-7 cells that express endogenous EGFR. Only TKJM was immunoprecipitated with an antibody directed against the extracellular part of EGFR, and only TKJM was tyrosine phosphorylated by endogenous EGFR. Using SK-N-MC cells, which do not express endogenous EGFR, that were stably transfected with either wild-type EGFR or recombinant full-length EGFR lacking P13 demonstrated that P13 is required for appropriate receptor dimerization. Furthermore, mutant EGFR lacking P13 failed to be autophosphorylated. P13 is rich in basic amino acids and in silico modeling of the EGFR in conjunction with our results suggests a novel role for the juxtamembrane domain (JM) of EGFR in mediating intracellular dimerization and thus receptor kinase activation and function. (C) 2004 Elsevier Inc. All rights reserved.