Post-transcriptional regulation of TNF-alpha production

描述(申请人提供)：位于肿瘤坏死因子a转录本3‘非翻译区的腺嘌呤和富尿苷元件(ARE)调节信使核糖核酸 稳定性和翻译，以防止TNFa的过度表达。 依赖ARE的转录后调控需要RNA结合的活性 作为翻译抑制因子的蛋白质(例如TIA-L和TIAR)、rnRNA 稳定剂(如HUR)和信使核糖核酸(如AUF1和TTP)。令人惊讶的是 关于这些Are结合蛋白(ARE-Bps)是如何相互作用的知之甚少 调节肿瘤坏死因子α的表达。提亚-L(和/或提亚)提拔将军 伴随着环境压力和 脂多糖激活对肿瘤坏死因子α的选择性翻译抑制作用 巨噬细胞。翻译被抑制的文字记录会暂时累积在 离散的细胞质病灶称为应力颗粒(SGS)。我们假设 SG充当转换检查点，确定TNFa 成绩单被翻译或降级。我们进一步建议，这一决定 受到调节转录稳定性的ARE-Bps的影响(例如HUR、AUF1和 TTP)。我们将通过确定：i)短暂性脑缺血发作-L的效果来检验这些假说 抑制SGS在TNFa生产上的组装的截断突变体， 2)脂多糖诱导的巨噬细胞SGS的mRNA和蛋白组成 绑定到TNFa的Are-Bps的不同功能类是否在 合作、非合作或竞争的方式，以及iv)有何不同 ARE-BPS的功能类别合作调节TNFa的生产。 这些目标的完成将提高我们对ARE-BPS如何相互作用的理解 本条例旨在规范肿瘤坏死因子的生产。这些研究也可能确定分子 开发可用于口服的TNFa阻滞剂的目标 治疗类风湿性关节炎患者。

DESCRIPTION (provided by applicant): An adenine and uridine-rich element (ARE) located in the 3' untranslated region of TNF a transcripts regulates mRNA stability and translation in a way that prevents the overexpression of TNFa. ARE-dependent post-transcriptional control requires the activity of RNA-binding proteins that function as translational repressors (e.g. TIA-l and TIAR), rnRNA stabilizers (e.g. HuR) and mRNA destabilizers (e.g. AUF1 and TTP). Surprisingly little is known about how these ARE-binding proteins (ARE-BPs) interact to regulate the expression of TNFa. TIA-l (and/or TIAR) promote the general translational repression that accompanies environmental stress and the selective translational repression of TNFa that occurs in LPS-activated macrophages. Translationally repressed transcripts transiently accumulate at discrete cytoplasmic foci known as stress granules (SGs). We hypothesize that the SG functions as a translational checkpoint that determines whether TNFa transcripts are translated or degraded. We further propose that this decision is influenced by ARE-BPs that regulate transcript stability (e.g. HuR, AUF1 and TTP). We will test these hypotheses by determining: i) the effect of a TIA-l truncation mutant that inhibits the assembly of SGs on the production of TNFa, ii) the mRNA and protein composition of LPS-induced SGs in macrophages, iii) whether different functional classes of ARE-BPs bind to the TNFa ARE in a cooperative, non-cooperative or competitive manner, and iv) how different functional classes of ARE-Bps cooperate to regulate the production of TNFa. Completion of these aims will improve our understanding of how ARE-BPs interact to regulate the production of TNFa. These studies might also identify molecular targets for the development of orally available TNFa blockers that can be used to treat patients with rheumatoid arthritis.