BIOCHEMICAL AND TRANSLATION CONTROL OF CYTOKINE MRNA DEC

这一建议是针对一个新兴的但知之甚少的遗传控制领域，即哺乳动物细胞中短寿命mRNA的选择性细胞质降解，这是由mRNA （ARE- mRNA）的3‘非编码区（3’ ncr）中发现的富含au的元件（ARE）调节的。ARE促进mRNA快速降解的机制，翻译与ARE-mRNA快速降解之间的相互作用，以及促进ARE-mRNA选择性快速降解的细胞蛋白是本应用的主题。目的1将描述翻译在促进含有GM-CSF ARE的mrna的快速降解中所起的作用。are - mrna的翻译已被证明可以加速或激活它们的快速衰变。研究建议探讨翻译激活或促进re - mrna快速衰减的机制。一组研究将调查re - mrna的翻译如何促进其自身的快速衰变。其他研究将探讨是否必须持续合成短寿命反式作用细胞蛋白来促进ARE- mRNA的转换。目的2将研究re - mrna快速降解的分子机制。在哺乳动物细胞中，控制ARE mrna快速降解的基本分子机制基本上是未知的。被称为AUF1的特异性ARE结合蛋白家族促进ARE- mrna的快速衰减。AUF1与mRNA结合后，在体内与多种蛋白形成复合物，包括翻译起始因子eIF4G、聚(a)结合蛋白（PABP）和热休克蛋白hsp70和hsc70。实验旨在了解AUF1与are的结合如何促进are - mrna的快速衰变，以及eIF4G、PAPB和hsp- hsc70在are - mrna衰变中的作用。目的3将鉴定未知的AUF1结合蛋白，并研究它们在调节ARE mrna快速衰减中的作用。虽然研究已经确定了几种AUF1结合蛋白，但仍有其他结合蛋白在体内被检测到但尚未被鉴定。实验建议使用酵母2-杂交分析从遗传学上鉴定剩余的AUF1结合蛋白，并从生化角度研究这些蛋白在促进或抑制are - mrna衰变中的可能作用。

This proposal is directed to an emerging but poorly understand area of genetic control, the selective cytoplasmic degradation of short-lived mRNAs in mammalian cells, which is regulated by an AU-rich element (ARE) found in the 3' non-coding region (3'NCR) of the mRNA (ARE- mRNA). The mechanisms by which the ARE promotes rapid mRNA decay, the interplay between translation and rapid ARE-mRNA decay, and the cellular proteins that promote selective rapid degradation of ARE- mRNAs are the subject of this application. Aim 1 will characterize the role translation plays in promoting rapid degradation of mRNAs containing the GM-CSF ARE. Translation of ARE-mRNAs has been shown to accelerate or activate their rapid decay. Studies are proposed to investigate the mechanism by which translation activates or promotes rapid decay of ARE-mRNAs. One group of studies will investigate how translation of the ARE-mRNA promotes its own rapid decay. Other studies will address whether short-lived trans-acting cellular proteins must be continuously synthesized to promote ARE- mRNA turnover. Aim 2 will investigate the molecular mechanism by which ARE-mRNAs are targeted for rapid degradation. Essentially nothing is known about the fundamental molecular mechanisms that control rapid degradation of ARE mRNAs in mammalian cells. The specific ARE binding protein family known as AUF1 promotes the rapid decay of ARE-mRNAs. AUF1 bound to mRNA forms a complex in vivo with a number of proteins, including translation initiation factor eIF4G, poly(A) binding protein (PABP) and heat shock proteins hsp70 and hsc70. Experiments are proposed to understand how binding of AUF1 to the ARE facilities the rapid decay of ARE-mRNAs, and the roles of eIF4G, PAPB and hsp- hsc70 in ARE-mRNA decay. Aim 3 will identify unknown AUF1 binding proteins and examine their roles in regulating rapid decay of ARE mRNAs. Although studies have identified several AUF1 binding proteins, still other binding prote3ins have been detected in vivo but not identified Experiments are proposed to genetically identify remaining AUF1 binding proteins using a yeast 2- hybrid analysis, and to biochemically investigate possible roles of these proteins in promoting or inhibiting decay of ARE-mRNAs.