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Erythrocyte maturation through global remodeling of the proteome

通过蛋白质组的整体重塑实现红细胞成熟

基本信息

批准号：
10378459
负责人：
MARK D FLEMING
金额：
$ 56.39万
依托单位：
HARVARD MEDICAL SCHOOL
依托单位国家：
美国
项目类别：
财政年份：
2021
资助国家：
美国
起止时间：
2021-04-01 至 2025-03-31
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10378459
关键词：
Actinin Actins Address Anabolism Automobile Driving Binding Biochemical Biochemistry Biological Process Biology Bypass Cell Differentiation process Cells Cellular biology Centrosome Complex Crystallins Crystallography Cytoskeletal Modeling Cytoskeletal Proteins Cytoskeleton Data Development Dynein ATPase Enzymes Erythroblasts Erythrocytes Erythroid Erythroid Cells Eukaryotic Cell Family Generations Genes Genetic Genetic Translation Globin Goals Hemoglobin Hydrogen In Vitro Informatics Lens Fiber Leucine-Rich Repeat Maps Mass Spectrum Analysis Mediating Messenger RNA Microscopy Microtubules Mitochondrial Proteins Motor Activity Mus Mutate Myosin ATPase Network-based Phase Physiological Play Process Proteasome Binding Proteins Proteome Proteomics Radial Regulatory Pathway Reticulocytes Ribosomes Role Signal Transduction Specificity Spectrin System Testing Time Translational Regulation Translations Tubulin Ubiquitin Ubiquitin Like Proteins Ubiquitin-Conjugating Enzymes Ubiquitination Variant Vesicle Work base cell type crosslink dynactin erythroid differentiation fiber cell genetic regulatory protein interest milligram multicatalytic endopeptidase complex mutant novel preservation programs protein crosslink protein degradation reconstitution ribosome profiling structural biology transcriptome sequencing transcriptomics ubiquitin ligase

项目摘要

PROJECT SUMMARY / ABSTRACT As cells undergo extreme forms of terminal differentiation, they are able to accumulate specific proteins to exceptionally high levels–hundreds of milligrams per ml in the case of globins and crystallins. At the same time, almost all other cellular components are eliminated. How cells can carry out such vast programs of biosynthesis and degradation simultaneously has been almost a complete mystery. We proposed in 1995 that the ubiquitin-proteasome system (UPS) may play a central role in global proteome remodeling. Using murine reticulocytes, a uniquely powerful system to study global proteome remodeling, we found that indeed UBE2O, a ubiquitin-conjugating enzyme that is strongly induced in late erythroid differentiation, mediates the elimination of ribosomes and myriad other proteins via the proteasome. We proceeded to examine other UPS components that are strongly induced in erythroid cells, and found that TRIM10 eliminates dynactin, many myosins, actin crosslinking proteins, the erythroid regulator TMCC2, and COP1 vesicles; TRIM58 eliminates dynein and centrosomal proteins; the unique ubiquitin-like protein TBCEL specifically dismantles the tubulin cytoskeleton; and UBE2H, together with the GID complex, eliminates a broad set of mRNA-binding translational regulatory proteins while also promoting the elimination of many mitochondrial proteins. Thus, these UPS components have highly distinct specificities, each driving the elimination of different parts of the cell or proteome. This work uncovers a vast new regulatory pathway that appears to be central to the maturation of the erythrocyte. It also indicates a remarkable new capacity of the UPS: to effect global and developmentally controlled proteomic remodeling. In contrast to the above-described proteins, most UPS components disappear during erythroid maturation; thus, a highly specialized variant of the UPS mediates remodeling. Focusing on TBCEL, TRIM10, and TRIM58, we will use biochemical reconstitution, crystallography, and hydrogen exchange mass spectrometry to resolve specific mechanisms of degradation and degradation signals in target proteins. Cellular studies will focus on the cytoskeleton and on translational control as highlighted by our proteomic data. As the erythroblast matures into the red blood cell, its radial, microtubule-based cytoskeleton is replaced by an acentric actin-based network. We will characterize how the cytoskeleton functions during the unusual and to date uncharacterized transition period that takes place in the reticulocyte. We will then assess the impact of programmed elimination of tubulin and other cytoskeletal proteins on this cytoskeletal transformation. Although late erythroid cells are known to be characterized by extensive translational regulation, our findings indicate a new mechanism by which diverse translational regulators are themselves controlled. We will use our mutants to determine the impact of UBE2H-dependent ubiquitination on mRNA translation in reticulocytes, using RNA-Seq and Ribo-Seq in parallel. In summary, we propose that ubiquitin-dependent proteome remodeling is an important new aspect of the biology of eukaryotic cells, critical for the generation of highly differentiated cell types.

项目摘要/摘要