The United Graduate School of Agricultural Sciences, Iwate University, Morioka, Iwate 020-8550, Japan.
Department of Biomedical Sciences, Mercer University School of Medicine, Savannah, GA 31404, USA.
Int J Mol Sci. 2020 Feb 20;21(4):1429. doi: 10.3390/ijms21041429.
Steroidogenic Factor 1 (SF-1/NR5A1), an orphan nuclear receptor, is important for sexual differentiation and the development of multiple endocrine organs, as well as cell proliferation in cancer cells. Activating transcription factor 3 (ATF3) is a transcriptional repressor, and its expression is rapidly induced by DNA damage and oncogenic stimuli. Since both NR5A1 and ATF3 can regulate and cooperate with several transcription factors, we hypothesized that NR5A1 may interact with ATF3 and plays a functional role in cancer development. First, we found that NR5A1 physically interacts with ATF3. We further demonstrated that ATF3 expression is up-regulated by NR5A1. Moreover, the promoter activity of the is activated by NR5A1 in a dose-dependent manner in several cell lines. By mapping the promoter as well as the site-directed mutagenesis analysis, we provide evidence that NR5A1 response elements (-695 bp and -665 bp) are required for expression by NR5A1. It is well known that the transcriptional activities of NR5A1 are modulated by post-translational modifications, such as small ubiquitin-related modifier (SUMO) modification and phosphorylation. Notably, we found that both SUMOylation and phosphorylation of NR5A1 play roles, at least in part, for NR5A1-mediated expression. Overall, our results provide the first evidence of a novel relationship between NR5A1 and ATF3.
类固醇生成因子 1（SF-1/NR5A1）是一种孤儿核受体，对于性分化和多种内分泌器官的发育以及癌细胞的增殖都很重要。激活转录因子 3（ATF3）是一种转录抑制剂，其表达可被 DNA 损伤和致癌刺激迅速诱导。由于 NR5A1 和 ATF3 都可以调节和与几个转录因子合作，我们假设 NR5A1 可能与 ATF3 相互作用，并在癌症发展中发挥功能作用。首先，我们发现 NR5A1 与 ATF3 发生物理相互作用。我们进一步证明，NR5A1 可上调 ATF3 的表达。此外，NR5A1 以剂量依赖性方式在几种细胞系中激活 的启动子活性。通过对 启动子以及定点突变分析进行作图，我们提供了证据，表明 NR5A1 反应元件（-695 bp 和-665 bp）是 NR5A1 表达所必需的。众所周知，NR5A1 的转录活性受到翻译后修饰的调节，如小泛素相关修饰物（SUMO）修饰和磷酸化。值得注意的是，我们发现 NR5A1 的 SUMO 化和磷酸化都至少部分地参与了 NR5A1 介导的 表达。总的来说，我们的结果首次提供了 NR5A1 和 ATF3 之间存在新关系的证据。
