DC 欄位 | 值 | 語言 |
dc.contributor | 呂勝春 | zh-TW |
dc.contributor | 臺灣大學:分子醫學研究所 | zh-TW |
dc.contributor.author | 柯佳瑜 | zh-TW |
dc.contributor.author | Ke, Jia-Yu | en |
dc.creator | 柯佳瑜 | zh-TW |
dc.creator | Ke, Jia-Yu | en |
dc.date | 2008 | en |
dc.date.accessioned | 2010-05-04T06:56:22Z | - |
dc.date.accessioned | 2018-07-09T01:10:35Z | - |
dc.date.available | 2010-05-04T06:56:22Z | - |
dc.date.available | 2018-07-09T01:10:35Z | - |
dc.date.issued | 2008 | - |
dc.identifier.other | U0001-2507200817480500 | en |
dc.identifier.uri | http://ntur.lib.ntu.edu.tw//handle/246246/178670 | - |
dc.description.abstract | CAAT區/增强子结合蛋白 beta (C/EBP beta) 是一個重要的轉錄因子,而且在許多細胞反應扮演重要的角色。當內質網 (endoplasmic reticulum) 內未折疊或錯折疊蛋白積聚時,就會對內質網產生壓力,也就是所謂的 ER stress 。在 ER stress 的情況下, C/EBP beta 的表現量會增加。 C/EBP beta 有三個轉譯產物,皆從同一條 mRNA 轉譯出來,其中有兩個是轉錄活化因子 (LAP* 和 LAP),另一個則是轉錄抑制因子 (LIP)。三個轉譯產物之間的相對量對於 C/EBP beta 下游基因的調控很重要。本篇發現了在 thapsigargin 和低濃度的 anisomycin 環境下, C/EBP beta 三個轉譯產物的表現量會改變。而低濃度的 anisomycin 已知亦會產生 ER stress 。我們也發現在 anisomycin 的處理下,用 C/EBP beta 的抗體可偵測到有未知的 C/EBP beta 產物表現出來。除此之外,有一個小的 open reading frame (sORF) 穿插在 C/EBP beta 的 mRNA 會影響 LAP 跟 LIP 的表現。之前研究對於 sORF 如何調控下游 LIP 的轉譯,有兩種說法: 一個模式是核糖體的 leaky scanning ,而另一種是 re-initiation 。在本篇,我們的結果支持 LIP 的轉譯是經由 re-initiation 模式. | zh-TW |
dc.description.abstract | C/EBP beta is a transcription factor that belongs to the C/EBP family and plays important roles in many cellular responses. C/EBP beta expression increases during endoplasmic reticulum (ER) stress, which is triggered by the accumulation of unfolded proteins in the ER. Three isoforms, LAP*, LAP and LIP, are translated at alternative initiation codons of an intronless mRNA. LAP* and LAP are transcriptional activators, while LIP is a dominant-negative repressor. The relative expression of three isoforms is critical for C/EBP beta-mediated gene transcription. This report showed that the expression of C/EBP beta isoforms changed in response to thapsigargin and low dose anisomycin, which can trigger ER stress. We also found novel protein bands triggered by anisomycin treatment. An out-of-frame AUG codon of small open reading frame (sORF) in mRNA has been reported that regulated LAP and LIP expression. In this report, our data supported the model that translation of LIP is mediated by re-initiation model, in which the 40S ribosomal subunit remains attached to the mRNA after termination of the uORF, and re-initiates scanning. | en |
dc.description.tableofcontents | 摘要 iiibstract ivontents vntroduciton 1aterial and methods 8NA constructs 8ell culture 10NA transfection 10reparation of Whole Cell Extraction 11DS-PAGE 11estern blot analysis 13uciferase assay 14esults 15nduction of LIP or an unknown isoform in response to stress. 15he induction of LIP by ER stress is independent of sORF-AUG codon. 16irefly luciferase activity is not simply regulated by sORF 17ultiple C/EBPβ isoforms are generated by alternative translation initiation and the sORF is important for the translation of LIP via re-initiation. 18hanged pool level of C/EBPβ isoforms in response to anisomycin and thapsigargin. 21iscussion 24eferences 29ist of Figures 32igure 1. Western analysis of the C/EBPβ isoforms of wild-type and sORF-AUG mutated expression vector (mtsORF). 32igure 2. Western analysis of 34igure 3. Western analysis of C/EBPβ isoforms of wild-type and mtsORF expression vector when treated with drugs. 35igure 4. Luciferase activity is regulated by different AUG mutants. 36igure 5. Western analysis of wild-type C/EBPβ expression vectors, expression vectors with mutation at multiple AUG initiation codon, and mutation of the sORF-AUG. 38igure 6. Western analysis of C/EBPβ isoforms of mtAUG-1 and mtAUG-1&mtsORF expression vector when treated with drugs. 40igure 7. Western analysis of C/EBPβ isoforms of mtAUG-2 and mtAUG-2&mtsORF expression vector when treated with drugs. 41igure 8. Western analysis of C/EBPβ isoforms of mtAUG1&2 and 3mtAUG expression vector when treated with drugs. 42igure 9. Western analysis of C/EBPβ isoforms of LAP and LIP expression vector when treated with drugs. 43igure 10. Western analysis of endogenous C/EBPβ isoforms expression in RAW 264.7 in response to thapsigargin and anisomycin. 44ist of Tables 46able 1. 46able 2. 48 | en |
dc.format | application/pdf | en |
dc.format.extent | 2576675 bytes | - |
dc.format.mimetype | application/pdf | - |
dc.language | en | en |
dc.language.iso | en_US | - |
dc.subject | CAAT區/增强子结合蛋白 | zh-TW |
dc.subject | 轉錄活化因子 | zh-TW |
dc.subject | 轉譯產物 | zh-TW |
dc.subject | C/EBP beta | en |
dc.subject | anisomycin | en |
dc.subject | thapsigargin | en |
dc.subject | leaky scanning | en |
dc.subject | re-initiation | en |
dc.title | CAAT區/增强子结合蛋白 beta(C/EBP beta)不同轉譯產物的調控 | zh-TW |
dc.title | Regulation of C/EBP beta isoforms | en |
dc.identifier.uri.fulltext | http://ntur.lib.ntu.edu.tw/bitstream/246246/178670/1/ntu-97-R95448006-1.pdf | - |
item.languageiso639-1 | en_US | - |
item.grantfulltext | open | - |
item.fulltext | with fulltext | - |
顯示於: | 分子醫學研究所
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