Phosphorylation of Y845 on the epidermal growth factor receptor mediates binding to the mitochondrial protein cytochrome c oxidase subunit II
Phosphorylation of Y845 on the epidermal growth factor receptor mediates binding to the mitochondrial protein cytochrome c oxidase subunit II
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DOI：
10.1128/mcb.24.16.7059-7071.2004
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发表时间：
2004-08-01
影响因子：
5.3
通讯作者：
Parsons, SJ
中科院分区：
文献类型：
--
作者：
Boerner, JL;Demory, ML;Parsons, SJ
当共同过表达时，表皮生长因子受体（EGFR）和c-Src合作，导致协同增加EGF诱导的DNA合成，软琼脂集落生长，裸鼠肿瘤形成。这种协同作用依赖于c-Src介导的EGFR上独特酪氨酸的磷酸化，即酪氨酸845（Y845）。发现Y845（Y845 F）的苯丙氨酸取代抑制EGF诱导的DNA合成，而不影响受体的催化活性或其磷酸化She或激活促分裂原活化蛋白激酶的能力。这些结果表明，协同作用可能通过磷酸化Y845（pY 845）介导的替代信号通路发生。一种这样的途径涉及转录因子Stat 5 b。在这里，我们描述了另一种途径，涉及细胞色素c氧化酶亚基II（CoxII）。在噬菌体展示筛选中，CoxII被鉴定为含有pY 845的肽的特异性结合伴侣。通过共免疫沉淀实验证实了CoxII与野生型但不与突变型Y845 F-EGFR的EGF依赖性结合。这种关联也需要c-Src的激酶活性。共聚焦显微镜，以及生化分馏，表明表皮生长因子受体易位到线粒体EGF刺激后，在那里它与CoxII共定位。这种转运需要受体的催化活性，但不需要Y845的磷酸化。然而，异位表达的Y845 F-EGFR阻止EGF保护MDA-MB-231乳腺癌细胞免受阿霉素诱导的凋亡，而两个突变的Stat 5 b，显性干扰突变（DNstat 5 b）和酪氨酸突变699（Y 699 F-Stat 5 b）没有。综上所述，这些数据表明，通过EGFR易位到线粒体的能力，蛋白质如CoxII与EGFR上的pY 845的结合可以积极调节有助于肿瘤发生的存活途径。
When co-overexpressed, the epidermal growth factor receptor (EGFR) and c-Src cooperate to cause synergistic increases in EGF-induced DNA synthesis, soft agar colony growth, and tumor formation in nude mice. This synergy is dependent upon c-Src-mediated phosphorylation of a unique tyrosine on the EGFR, namely, tyrosine 845 (Y845). Phenylalanine substitution of Y845 (Y845F) was found to inhibit EGF-induced DNA synthesis without affecting the catalytic activity of the receptor or its ability to phosphorylate She or activate mitogen-activated protein kinase. These results suggest that synergism may occur through alternate signaling pathways mediated by phosphorylated Y845 (pY845). One such pathway involves the transcription factor Stat5b. Here we describe another pathway that involves cytochrome c oxidase subunit II (CoxII). CoxII was identified as a specific binding partner of a pY845-containing peptide in a phage display screen. EGF-dependent binding of CoxII to the wild type but not to the mutant Y845F-EGFR was confirmed by coimmuno-precipitation experiments. This association also required the kinase activity of c-Src. Confocal microscopy, as well as biochemical fractionation, indicated that the EGFR translocates to the mitochondria after EGF stimulation, where it colocalizes with CoxII. Such translocation required the catalytic activity of the receptor but not phosphorylation of Y845. However, ectopic expression of the Y845F-EGFR prevented the EGF from protecting MDA-MB-231 breast cancer cells from adriamycin-induced apoptosis, whereas two mutants of Stat5b, a dominant-interfering mutant (DNstat5b) and a tyrosine mutation at 699 (Y699F-Stat5b) did not. Taken together, these data suggest that, through the ability of EGFR to translocate to the mitochondria, the binding of proteins such as CoxII to pY845 on the EGFR may positively regulate survival pathways that contribute to oncogenesis.