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Regulation of Ribosome Biogenesis in Hematopoietic Stem Cells

造血干细胞核糖体生物合成的调控

基本信息

批准号：
10472622
负责人：
Wei Tong
金额：
$ 60.24万
依托单位：
CHILDREN'S HOSP OF PHILADELPHIA
依托单位国家：
美国
项目类别：
财政年份：
2020
资助国家：
美国
起止时间：
2020-09-18 至 2025-08-31
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10472622
关键词：
Affect Allogenic Biochemical Biogenesis Biological Blood Blood Cells Bone Marrow Bone Marrow Transplantation Bone marrow failure Cell Line Cell Maintenance Cell physiology Cells Clinical Clinical Treatment Collaborations Cytoplasm Data Defect Disease Equilibrium Etiology Exhibits Failure Functional disorder Gene Proteins Genes Genetic Genetic Suppression Genomics Goals Growth Hematopoiesis Hematopoietic Hematopoietic stem cells Human Knockout Mice Link Malignant Neoplasms Marrow Mediating Mutation Myeloproliferative disease Pathway interactions Patients Polyribosomes Population Predisposition Prokaryotic Cells Protein Biosynthesis Proteins Proteomics Registries Regulation Research Ribosomal Proteins Ribosomes Role Shwachman-Diamond syndrome Signal Transduction Stem cell transplant Structure Syndrome Testing Therapeutic Therapeutic Intervention Translation Process Protein Translations Transplantation Ubiquitin Ubiquitination Validation Yeasts base bone marrow failure syndrome cancer predisposition cell growth conditional knockout epigenomics exome sequencing genetic analysis in vivo insight interest knock-down novel novel therapeutic intervention novel therapeutics polypeptide prevent programs reconstitution ribosome profiling self-renewal small hairpin RNA stem cell function stem cells transcriptome transcriptome sequencing treatment strategy ubiquitin-protein ligase

项目摘要

Abstract Tightly-regulated protein synthesis rates are critical for hematopoietic stem cell (HSC) maintenance and function. Mutations in ribosome proteins or genes that affect ribosome biogenesis cause “ribosomopathies”, a class of bone marrow failure (BMF) syndromes. As prominently illustrated by Shwachman-Diamond Syndrome (SDS), a BMF disease with progressive hematopoietic stem and progenitor cell (HSPC) failure and predisposition to myeloid malignancies, is driven by germline biallelic mutations in the assembly factors essential for the maturation of the 60S ribosome subunit. However, how ribosome assembly is regulated in HSCs remains poorly understood, as is its contribution to hematopoietic dysfunction. Importantly, other than allogeneic stem cell transplantation, therapeutic interventions that mitigate the HSPC defects in BMF do not exist. This application is based on our new studies that uncovered a novel role for the E3 ubiquitin ligase, HectD1, in regulating HSC function via ribosome biogenesis. Hectd1-deficient HSCs exhibit a striking defect in transplantation ability and self-renewal, concomitant with a reduction in global protein synthesis. The mechanism underlying HSC dysfunction upon Hectd1 deficiency is directly linked to aberrant ribosome assembly by ubiquitinating and regulating the stability of ZNF622, a critical biogenesis factor for the maturation of the 60S large ribosomal subunit in the cytoplasm. Depletion of HectD1 led to an accumulation of ZNF622 and the anti-association factor eIF6 on the 60S subunit, decreased 80S monosome to 60S ratio, consistent with a subunit joining defect associated with SDS-like diseases. Importantly, knockdown of ZNF622 in Hectd1-deficient cells restored protein synthesis and HSC reconstitution capacity. This finding represents a rare in vivo example of genetic suppression of HSC defects associated with dysfunctional ribosome biogenesis. The implications of this novel pathway to the etiology of HSC failure and clinical treatment of “ribosomopathies”, mandates detailed mechanistic understanding. Here, we propose comprehensive and in-depth analyses on the role of HectD1 and ZNF622 in ribosome biogenesis and HSCs. In aim 1, we propose to investigate the roles of HectD1 and ZNF622 in HSCs and how they interact to regulate HSC function, using a combination of complementary genetics, genomics, and biochemical approaches. In aim 2, we will systematically analyze if HectD1/ZNF622 affects different aspects of protein translation controls. Moreover, we will perform quantitative proteomics to assess if ribosome levels or ribosome composition is affected by Hectd1/ZNF622 loss. In aim 3, we will interrogate potential dysregulation of HECTD1 and ZNF622 in human BMF syndromes and explore therapeutic potential of targeting ZNF622 for the treatment of BMF with dysfunctional ribosome biogenesis. Our study implicates a previously unappreciated role of ubiquitination in regulating HSC function via controlling ribosome biogenesis factors, which are dysregulated in ribosomopathies. Our findings will likely have significant impact on the therapeutic potential of modulating ubiquitination and/or ribosome biogenesis factors in restoring HSC functions in BMF syndromes.

摘要