精氨酸甲基化酵素-6與林巴促進因子結合以增強基因活化之研究

Abstract

Wnt訊息傳遞調控發育過程， 而該訊息的失控將會導致癌症的發生。Wnt分子藉由LEFs/beta-catenin來達成訊號傳遞的結果。在Wnt訊號的刺激下，beta-catenin累積在細胞質中並進入到細胞核內與LEFs結合活化特定基因。已知一些蛋白質會與beta-catenin/LEFs結合並增加或抑制beta-catenin/LEFs對於基因活化的能力。為了要尋找其他會影響beta-catenin/LEFs活化基因能力的蛋白質，我們利用LEFs家族中的兩個蛋白質LEF在酵母菌雙雜交法中當作餌在胚胎腦細胞基因庫與乳腺細胞基因庫中尋找會與LEF1或作用的蛋白質。最後找到了PRMT6，並利用GST拉下法及免疫沉澱法證明PRMT6的確會與LEF1作用。也以轉錄報導基因證實PRMT6會增進beta-catenin/LEF1活化基因的能力。

Wnt signals control developmental processes and its deregulation leads to various cancers. Wnt molecules transduce signals through beta-catenin/LEFs(LEF1, TCF4 and its homologs). Upon wnt signaling, beta-catenin accumulates and associates with LEFs to transactivate specific genes. LEFs are required for body plan formation, cell fate determination, cells proliferation and survival. It was well known that various proteins, such as CBP, HDAC, PIAS, and Groucho-related proteins, participated in LEFs/beta-catenin transcriptional activity. Here, we performed yeast two-hybrid screening through fetal brain libraray and mammary gland library to search additional proteins involved in LEFs/beta-catenin transcriptional activity. PRMT6 was identified to interact with LEF1 both in vivo and in vitro. It was also shown to enhance LEF1/beta-catenin transcriptional activity on reporter assay.