Regulation of hematopoiesis by ribosomal protein paralogs

核糖体蛋白旁系同源物对造血的调节

• 批准号: 10548846
• 负责人: DAVID L. WIEST
• 金额: $ 56.1万
• 依托单位: RESEARCH INST OF FOX CHASE CAN CTR
• 依托单位国家: 美国
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-07-18 至 2025-01-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10548846
• 关键词: Ablation; Acute Myelocytic Leukemia; Address; Adult; Anemia; Attenuated; Binding; Biogenesis; Biological Process; Biology; Dependence; Development; Disease; Disease Progression; Distal; Dysmyelopoietic Syndromes; Embryo; Erythroid; Functional disorder; Future; Gene Expression; Gene Proteins; Health; Hematologic Neoplasms; Hematopoiesis; Hematopoietic; Hematopoietic Stem Cell Transplantation; Hematopoietic stem cells; Human; Hydroxyeicosatetraenoic Acids; In Vitro; Knowledge; Ligands; Link; Lipids; Lipoxygenase; Malignant Neoplasms; Mediating; Mediator; Messenger RNA; Metabolism; Myelogenous; Pathway interactions; Play; Positioning Attribute; Process; Protein Biosynthesis; RNA; RNA Binding; RNA Splicing; RNA Stability; Regulation; Repression; Ribosomal Proteins; Ribosomes; Role; Signal Transduction; Specificity; Stem Cell Development; T-Cell Development; Testing; Therapeutic; Tissues; Translations; Zebrafish; antagonist; arachidonate; attenuation; cancer immunotherapy; cell behavior; combinatorial; experimental study; falls; fatty acid oxidation; fetal; hematopoietic stem cell emergence; hematopoietic stem cell self-renewal; immune checkpoint blockade; insight; link protein; loss of function; mRNA Translation; mouse model; novel; novel strategies; novel therapeutic intervention; paralogous gene; progenitor; protein function; reconstitution; stem cell biology; stem cell function; synergism

PROJECT SUMMARY/ABSTRACT Ribosomal proteins (RP) are increasingly understood to play crucial regulatory roles in development and disease; however, the way they do so remains unclear. The potential modes of RP action fall into two classes: effects on the ribosome itself or extraribosomal functions carried out while physically separate from the ribosome. Traditional loss-of-function approaches to address RP function fail to distinguish these modes of action because most RP are essential for ribosome biogenesis and/or function and so ablation of such RP genes attenuates both modes of action. Consequently, an unequivocal determination of the contributions of extraribosomal RP functions to biological processes remains a critical gap in knowledge. Importantly, we have identified an RP, Rpl22, which is not required for ribosome biogenesis or function, but nevertheless plays critical, selective roles in hematopoiesis. Rpl22 not only regulates hematopoietic stem cell (HSC) emergence in the embryo but also regulates adult HSC function, as well as more distal stages of hematopoiesis including B and T lymphocyte development. The basis for the selective requirement for Rpl22 in particular hematopoietic processes remains unclear; however, we have recently determined that the capacity of Rpl22 to regulate fetal HSC emergence is dependent upon its physical association with hnRNP-A1, which can regulate translation. Moreover, hnRNP-A1 selectively associates with Rpl22 molecules that are physically separate from the ribosome. Consequently, we have an unprecedented opportunity to investigate the importance of the extraribosomal function of Rpl22 in hematopoiesis. We hypothesize that Rpl22 regulates hematopoiesis chiefly through its extraribosomal activity, by associating with hnRNP-A1, and regulating the translation, splicing and possibly the stability of RNA targets that differ depending on the cellular context. Indeed, while Rpl22 controls fetal HSC emergence by regulating the expression of Smad1, Rpl22 controls adult HSC behavior by regulating the expression of a lipoxygenase (Alox12), which generates lipid species that activate PPARd, a master regulator of fatty acid oxidation (FAO). As FAO has been shown to regulate HSC self-renewal, we hypothesize that Rpl22 regulates Alox12 signaling to maintain HSCs. In this proposal, we will test these hypotheses in two aims. Aim 1 seeks to determine how the Rpl22/hnRNP-A1 axis exerts its functions in controlling HSC biology, and identify the specific Rpl22-regulated fetal and adult hematopoietic processes that depend on Rpl22 association with hnRNP-A1. Aim2 focuses on investigating the mechanism and role of downstream Alox12-driven FAO pathways through which Rpl22 controls adult HSC function. In pursing these studies, we will integrate cutting edge structural analysis with the unique strengths of zebrafish and a variety of novel mouse models, and verify core findings in human progenitors. Together, these studies will provide the first insight into the novel, extraribosomal “moonlighting” functions through which RP regulate biological processes, and may reveal the basis for the tissue specificity of Rpl22- dependence displayed by particular hematopoietic processes.

项目概要/摘要 人们越来越认识到核糖体蛋白 (RP) 在发育和疾病中发挥着至关重要的调节作用； 然而，他们这样做的方式仍不清楚 RP 作用的潜在模式分为两类：对的影响。 核糖体本身或核糖体外功能在物理上与核糖体分离时进行。 解决 RP 功能的传统功能丧失方法无法区分这些作用模式，因为 大多数 RP 对于核糖体生物发生和/或功能至关重要，因此消除此类 RP 基因会减弱 对两种作用方式进行了检查，明确确定了核糖体外 RP 的贡献。 重要的是，我们已经确定了 RP， Rpl22，不是核糖体生物发生或功能所必需的，但仍然起着关键的选择性作用 Rpl22 不仅调节胚胎中的造血干细胞 (HSC) 的出现。 调节成人 HSC 功能以及造血的更远端阶段，包括 B 和 T 淋巴细胞 特定造血过程中对 Rpl22 的选择性需求的基础仍然存在。 尚不清楚；然而，我们最近确定 Rpl22 调节胎儿 HSC 出现的能力是 取决于其与 hnRNP-A1 的物理关联，而 hnRNP-A1 可以调节翻译。 我们检查了与物理上分离的 Rpl22 分子的选择性结合。 有一个前所未有的机会来研究 Rpl22 核糖体外功能的重要性 我们认为 Rpl22 主要通过其核糖体外活性调节造血作用， 通过与 hnRNP-A1 结合，调节 RNA 靶标的翻译、剪接以及可能的稳定性 事实上，这取决于细胞环境，而 Rpl22 通过调节来控制胎儿 HSC 的出现。 Smad1、Rpl22 的表达通过调节脂氧合酶的表达来控制成人 HSC 的行为 (Alox12)，它产生激活 PPARd 的脂质物质，PPARd 是脂肪酸氧化 (FAO) 的主要调节因子。 FAO 已被证明可以调节 HSC 自我更新，我们欺负 Rpl22 调节 Alox12 信号传导 在本提案中，我们将在两个目标中测试这些假设，以确定如何实现。 Rpl22/hnRNP-A1轴在控制HSC生物学中发挥其功能，并识别Rpl22调节的特异性 胎儿和成人的造血过程依赖于 Rpl22 与 hnRNP-A1 的关联。 研究Rpl22控制的下游Alox12驱动的FAO途径的机制和作用 在进行这些研究时，我们将尖端的结构分析与独特的功能相结合。 斑马鱼和各种新型小鼠模型的优势，并验证人类祖细胞的核心发现。 总之，这些研究将首次深入了解核糖体外的新型“兼职”功能 RP 通过其调节生物过程，并可能揭示 Rpl22- 组织特异性的基础 特定造血过程表现出的依赖性。