Uranishi H, Tetsuka T, Yamashita M, Asamitsu K, Shimizu M, Itoh M, Okamoto T
Department of Molecular Genetics and First Department of Internal Medicine, Nagoya City University Medical School, 1 Kawasumi, Mizuho-cho, Mizuho-ku, Nagoya, Aichi 467-8601, Japan.
J Biol Chem. 2001 Apr 20;276(16):13395-401. doi: 10.1074/jbc.M011176200. Epub 2001 Jan 24.
In this study, we have demonstrated that translocated in liposarcoma (TLS), also termed FUS, is an interacting molecule of the p65 (RelA) subunit of the transcription factor nuclear factor kappaB (NF-kappaB) using a yeast two-hybrid screen. We confirmed the interaction between TLS and p65 by the pull-down assay in vitro and by a coimmunoprecipitation experiment followed by Western blot of the cultured cell in vivo. TLS was originally identified as part of a fusion protein with CHOP arising from chromosomal translocation in human myxoid liposarcomas. TLS has been shown to be involved in TFIID complex formation and associated with RNA polymerase II. However, the role of TLS in transcriptional regulation has not yet been clearly elucidated. We found that TLS enhanced the NF-kappaB-mediated transactivation induced by physiological stimuli such as tumor necrosis factor alpha, interleukin-1beta, and overexpression of NF-kappaB-inducing kinase. TLS augmented NF-kappaB-dependent promoter activity of the intercellular adhesion molecule-1 gene and interferon-beta gene. These results suggest that TLS acts as a coactivator of NF-kappaB and plays a pivotal role in the NF-kappaB-mediated transactivation.
在本研究中，我们通过酵母双杂交筛选证明，在脂肪肉瘤中易位的蛋白（TLS），也称为FUS，是转录因子核因子κB（NF-κB）的p65（RelA）亚基的相互作用分子。我们通过体外下拉试验以及体内培养细胞的免疫共沉淀实验和随后的蛋白质印迹法，证实了TLS与p65之间的相互作用。TLS最初被鉴定为人类黏液样脂肪肉瘤中由染色体易位产生的与CHOP融合蛋白的一部分。已证明TLS参与TFIID复合物的形成并与RNA聚合酶II相关。然而，TLS在转录调控中的作用尚未得到明确阐明。我们发现，TLS增强了由生理刺激（如肿瘤坏死因子α、白细胞介素-1β）以及NF-κB诱导激酶的过表达所诱导的NF-κB介导的反式激活。TLS增强了细胞间黏附分子-1基因和干扰素-β基因的NF-κB依赖性启动子活性。这些结果表明，TLS作为NF-κB的共激活因子，在NF-κB介导的反式激活中起关键作用。
