Requirement of protein l-isoaspartyl O-methyltransferase for transcriptional activation of trefoil factor 1 (TFF1) gene by estrogen receptor alpha

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• 作者：Jong Woo Park^a ; ¹ ; Jae Cheol Lee^a ; ¹ ; Shin Won Ha^a ; So Young Bang^a ; Eun Kyung Park^a ; Sang Ah Yi^a ; Min Gyu Lee^a ; Dae Sung Kim^a ; Ki Hong Nam^a ; Ji Hee Yoo^a ; So Hee Kwon^b ; ^{soheekwon@yonsei.ac.kr} ; Jeung-Whan Han^a ; ^{jhhan551@skku.edu}
• 关键词：PIMT ; Protein methylation ; Co-activator ; Transcriptional regulation
• 刊名：Biochemical and Biophysical Research Communications
• 出版年：2012
• 期刊代码：159_0006291x
• 类别：bio
• 出版时间：6 April, 2012
• 卷：420
• 期：2
• 页码：223-229
• 文件大小：598 K

摘要

Lysine- and arginine-specific methyltransferases have been shown to act as either direct or secondary transcriptional co-activator of the estrogen receptor (ER伪). However, little is known about the role of protein l-isoaspartyl O-methyltransferase (PIMT) on transcriptional regulation. Here, we show that PIMT acts as a co-activator for ER伪-mediated transcription. Activation of the estrogen response element (ERE) promoter by 尾-estradiol (E₂) was suppressed by knockdown of PIMT, and enhanced by overexpression of wild-type PIMT. However, the ERE promoter activity was resistant to E₂ stimulation in cells overexpressing a catalytically inactive PIMT mutant, G88A. Consistent with these results, the expression of the endogenous ER伪 response gene trefoil factor 1 (TFF1) by E₂ was completely abrogated by PIMT depletion and decreased to approximately 50%when PIMT mutant G88A was expressed. In addition, over-expression of PIMT significantly increased the levels of TFF1 mRNA in the presence or absence of E₂. Interestingly, PIMT interacted with ER伪 and was distributed to the cytosol and the nucleus. The chromatin immunoprecipitation analysis revealed that PIMT was recruited to the promoter of TFF1 gene together with ER伪 in an E₂-dependent manner, which was accompanied by uploading of RNA polymerase II on the promoter. Taken together, the results suggest that PIMT may act as a co-activator in ER伪-mediated transcription through its recruitment to the promoter via interacting with ER伪.