Interferon regulatory factor-1 (IRF-1) is a transcription factor in humans that plays a crucial role in creating an antiviral state in infected cells and regulating cell cycle progression. Human IRF-1 is a modular protein with different functional domains. To investigate its functionality, we generated a truncated mutant version of human IRF-1, containing amino acids 1 to 233, compared to the wild-type IRF-1 with 325 amino acids (aa). We employed semi-nested PCR and techniques of cloning genes in both E. coli and mammalian expression vectors to produce the recombinant truncated Glutathione S-transferases tagged IRF-1 protein of molecular weight approximately 52 kDa. 12.5% SDS-PAGE was used to verify the expression of the protein. We introduced the truncated and wild-type IRF-1 into Human Embryonic Kidney cell lines HEK293 and HEK293T and detected the recombinant proteins using immunoblotting. Interestingly, the truncated IRF-1 (∆ IRF-1) version had no impact on the chromosomal genes including Bax, Bcl-2, and Cyclin D1. Furthermore, the MTT experiment showed that HEK293 and HEK293T cells were unaffected by the mutant IRF-1 in terms of proliferation and division. These results emphasize the importance of human IRF-1's amino acids 234–325 for the expression of the Bax, Bcl-2, and Cyclin D1 genes in this experimental paradigm. Consequently, this research offers significant information regarding the role of the human IRF-1 C-terminal domain.

干扰素调节因子-1 (IRF-1) 是人类的一种转录因子，在受感染细胞中产生抗病毒状态和调节细胞周期进程中发挥着至关重要的作用。人类 IRF-1 是一种具有不同功能域的模块化蛋白。为了研究其功能，我们生成了人类 IRF-1 的截短突变体版本，其中包含氨基酸 1 至 233，而野生型 IRF-1 则包含 325 个氨基酸 (aa)。我们采用半巢式PCR和在大肠杆菌和哺乳动物表达载体中克隆基因的技术来产生重组截短的谷胱甘肽S-转移酶标记的IRF-1蛋白，分子量约为52 kDa。采用12.5% SDS-PAGE验证蛋白表达。我们将截短的野生型IRF-1引入人胚肾细胞系HEK293和HEK293T中，并使用免疫印迹法检测重组蛋白。有趣的是，截短的 IRF-1 (Δ IRF-1) 版本对染色体基因（包括Bax、Bcl-2和Cyclin D1 ）没有影响。此外，MTT实验表明，突变型IRF-1对HEK293和HEK293T细胞的增殖和分裂没有影响。这些结果强调了人 IRF-1 的氨基酸 234-325 对于该实验范例中Bax、Bcl-2和Cyclin D1基因表达的重要性。因此，这项研究提供了有关人类 IRF-1 C 末端结构域作用的重要信息。