HPV16 E5 affects the KGFR/FGFR2b-mediated epithelial growth through alteration of the receptor expression, signaling and endocytic traffic
HPV16 E5 affects the KGFR/FGFR2b-mediated epithelial growth through alteration of the receptor expression, signaling and endocytic traffic
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DOI：
10.1038/onc.2011.203
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发表时间：
2011-12-01
期刊：
影响因子：
8
通讯作者：
Torrisi, M. R.
中科院分区：
文献类型：
--
作者：
Belleudi, F.;Leone, L.;Torrisi, M. R.
人乳头瘤病毒16型(HPV16E5)的E5蛋白在宫颈癌变和上皮转化中协同作用，通过调节生长因子受体来调节细胞的生长、存活和分化。在上皮性受体酪氨酸激酶中，角质形成细胞生长因子受体/成纤维细胞生长因子受体2b(KGFR/FGFR2b)是上皮细胞动态平衡的主要旁分泌调节因子，在上皮组织中具有独特的作用，在体外和体内都发挥着肿瘤抑制作用。为了更好地阐明16E5的病理活性所涉及的分子事件，我们研究了病毒蛋白是否能够通过干扰其降解和再循环的内吞途径来影响KGFR的表达、信号和周转。定量逆转录聚合酶链式反应和生化方法表明，E5蛋白能够在转录和蛋白水平诱导KGFR下调。在表达E5和KGFR的双转基因细胞中的免疫荧光显微镜显示，病毒蛋白改变了受体的内吞转运，并触发其内体分选到间接的核旁循环途径。从溶酶体降解到质膜循环的转变与成纤维细胞生长因子受体底物-2α酪氨酸196的磷酸化减少有关，成纤维细胞生长因子受体底物-2α酪氨酸196是Grb2-Cbl复合体的主要对接部位，负责受体泛素化和降解。5‘-溴脱氧尿苷掺入实验表明，16E5的表达导致KGFR下调导致对受体配体的生长反应减弱，提示16E5可能在HPV感染中通过干扰KGFR介导的融合角质形成细胞的生理行为而发挥作用。Oncogene(2011年)30,4963-4976；doi：10.1038/onc.2011.203；2011年5月30日在线发布
The E5 oncoprotein of the human papillomavirus type 16 (HPV16 E5) cooperates in cervical carcinogenesis and in epithelial transformation deregulating cell growth, survival and differentiation through the modulation of growth factor receptors. Among the epithelial receptor tyrosine kinases, the keratinocyte growth factor receptor/fibroblast growth factor receptor 2b (KGFR/FGFR2b) is a major paracrine mediator of epithelial homeostasis and appears to have an unique and unusual role in epithelial tissues, exerting a tumor-suppressive function in vitro and in vivo. With the aim to better elucidate the molecular events involved in the pathological activity of 16E5, we investigated if the viral protein would be able to affect the KGFR expression, signaling and turnover by interference with its degradative and recycling endocytic pathways. Quantitative reverse transcriptase-PCR and biochemical approaches on human keratinocytes transfected with 16E5-HA showed that E5 protein is able to induce KGFR down-modulation at both transcript and protein levels. Immunofluorescence microscopy in double-transfected cells expressing both E5 and KGFR revealed that the viral protein alters the receptor endocytic trafficking and triggers its endosomal sorting to the indirect juxtanuclear recycling pathway. The shift from lysosomal degradation to recycling at the plasma membrane correlates with a reduced phosphorylation of the fibroblast growth factor receptor substrate-2 alpha tyrosine 196, the major docking site for Grb2-Cbl complexes responsible for receptor ubiquitination and degradation. 5'-Bromo-deoxyuridine incorporation assay demonstrated that expression of 16E5 induces a decrease in the growth response to the receptor ligands as a consequence of KGFR down-modulation, suggesting that 16E5 might have a role on HPV infection in perturbing the KGFR-mediated physiological behavior of confluent keratinocytes committed to differentiation. Oncogene (2011) 30, 4963-4976; doi:10.1038/onc.2011.203; published online 30 May 2011