早幼粒細胞白血病蛋對HEK293細胞中金屬感應轉錄因子累積的作用

Effect of Promyelocytic leukemia protein on the accumulation of Metal responsive transcription factor 1 in HEK293 cells

陳彥賓(Chen,Yan Bin)

指導教授 ： 林立元

國立清華大學/生命科學院/分子與細胞生物研究所/碩士(2016年)

摘要

細胞在受到金屬刺激，金屬感應轉錄因子(MTF-1)會從細胞質進入細胞核內活化其下游基因，調節細胞內金屬濃度。過去實驗室發現砷離子會去促使MTF-1與早幼粒細胞白血病蛋白(PML)進行交互作用。在本實驗中發現在人類胚胎腎臟細胞(HEK293)細胞中PML會增加MTF-1蛋白質的累積量，並且不影響MTF-1的mRNA表現，而PML不同等型(isoform)之PML，PML I 到PMLVI皆可以去影響到MTF-1的累積量，不過在蛋白質穩定性的實驗下，PML並不會增加MTF-1的穩定性。實驗也發現MTF-1能夠被PML所影響蛋白質累積量的最小片段為N端到鋅指的區域，並且發現當把MTF-1的NLS訊號去除掉後會阻斷PML對MTF-1的影響，另外把PML的NLS訊號去除後並不會影響到PML對MTF-1的影響，所以MTF-1並非是核內PML小體所作用的對象。最後實驗也發現了雖然PML增加了MTF-1的蛋白質累積量，但是卻不改變其下游基因MT2A的表現量，這結果表示了PML所增加的MTF-1並非是用作為轉錄因子。

關鍵字

金屬感應轉錄因子

並列摘要

Metal-responsive transcription factor (MTF-1) regulate the gene related to metal homeostasis, which translocate to nucleus when heavy metal treatment. Previous studies indicated that As induced the interaction between MTF-1 and PML. In our experiment show that PML increase the protein expression of MTF-1 in the HEK293 cell, but does not alter the transcription of MTF-1 mRNA. The PML isoforms, PMLI to PMLVI cause MTF-1 protein accumulation without regulating MTF-1 protein stability. We found that the N-terminal including Zinc finger domain of MTF-1 accumulated by PML, and the deletion of MTF-1 NLS does not affect MTF-1 protein accumulation. Furthermore, the deletion of PML NLS would not affect MTF-1 protein accumulation, showing that MTF-1 is not a regulated protein of PML-NB. Finally, although we found that PML increases MTF-1 protein accumulation, but it does not alter the expression of MT2A, suggesting the increased MTF-1 caused by PML is not functional in the transcriptional level.

並列關鍵字

Metal responsive transcription factor 1

參考文獻

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