her-2 upstream open reading frame effects on the use of downstream initiation codons.
her-2 upstream open reading frame effects on the use of downstream initiation codons.
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DOI：
10.1016/j.bbrc.2006.09.128
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发表时间：
2006-12
影响因子：
3.1
通讯作者：
Christina C. Spevak;E. Park;A. Geballe;J. Pelletier;M. Sachs
中科院分区：
文献类型：
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作者：
Christina C. Spevak;E. Park;A. Geballe;J. Pelletier;M. Sachs
her-2（新的erbB-2）癌基因编码一个185 kda的跨膜受体酪氨酸激酶。HER2过表达发生在许多原发人类肿瘤中，导致25-30%的乳腺癌和卵巢癌。HER2的合成部分由转录物中存在的上游开放阅读框（uORF）控制。我们使用合成的盖帽和多腺苷化mrna，这些mrna包含her-2转录物的5 '区序列，融合到萤火虫荧光素酶（LUC）报告基因中，以检测该uORF在网状细胞、小麦胚芽和粗神经孢子虫等无细胞系统以及rna转染的HeLa细胞中对翻译的影响。在所有系统中，uORF减少了下游逆流的翻译。[35S]体外翻译产物的Met标记表明，uORF也影响下游起始位点的选择。网织细胞裂解物中装载起始密码子的核糖体的引物延伸抑制（引物延伸抑制）实验表明，uORF影响核糖体与her-2 AUG密码子的相互作用。
The her-2 (neu, erbB-2) oncogene encodes a 185-kDa transmembrane receptor tyrosine kinase. HER2 overexpression occurs in numerous primary human tumors and contributes to 25–30% of breast and ovarian carcinomas. Synthesis of HER2 is controlled in part by an upstream open reading frame (uORF) present in the transcript. We used synthetic capped and polyadenylated mRNAs containing sequences derived from the 5′ region of the her-2 transcript fused to a firefly luciferase (LUC) reporter to examine this uORF’s effect on translation in cell-free systems derived from reticulocytes, wheat germ and Neurospora crassa, and in RNA-transfected HeLa cells. The uORF reduced translation of the downstream cistron in all systems. [35S]Met labeling of in vitro translation products obtained indicated that the uORF also affected downstream start-site selection. Primer extension inhibition (toeprint) assays of ribosomes loaded at initiation codons in reticulocyte lysates indicated that the uORF affected the interaction of ribosomes with the primary her-2 AUG codon.