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Deryabin A, Moraleva A, Dobrochaeva K, Kovaleva D, Rubtsova M, Dontsova O, Rubtsov Y. Human RPF1 and ESF1 in Pre-rRNA Processing and the Assembly of Pre-Ribosomal Particles: A Functional Study. Cells 2024; 13:326. [PMID: 38391939 PMCID: PMC10886481 DOI: 10.3390/cells13040326] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2023] [Revised: 02/01/2024] [Accepted: 02/07/2024] [Indexed: 02/24/2024] Open
Abstract
Ribosome biogenesis is essential for the functioning of living cells. In higher eukaryotes, this multistep process is tightly controlled and involves a variety of specialized proteins and RNAs. This pool of so-called ribosome biogenesis factors includes diverse proteins with enzymatic and structural functions. Some of them have homologs in yeast S. cerevisiae, and their function can be inferred from the structural and biochemical data obtained for the yeast counterparts. The functions of human proteins RPF1 and ESF1 remain largely unclear, although RPF1 has been recently shown to participate in 60S biogenesis. Both proteins have drawn our attention since they contribute to the early stages of ribosome biogenesis, which are far less studied than the later stages. In this study, we employed the loss-of-function shRNA/siRNA-based approach to the human cell line HEK293 to determine the role of RPF1 and ESF1 in ribosome biogenesis. Downregulating RPF1 and ESF1 significantly changed the pattern of RNA products derived from 47S pre-rRNA. Our findings demonstrate that RPF1 and ESF1 are associated with different pre-ribosomal particles, pre-60S, and pre-40S particles, respectively. Our results allow for speculation about the particular steps of pre-rRNA processing, which highly rely on the RPF1 and ESF1 functions. We suggest that both factors are not directly involved in pre-rRNA cleavage but rather help pre-rRNA to acquire the conformation favoring its cleavage.
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Affiliation(s)
- Alexander Deryabin
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry RAS, 119997 Moscow, Russia
| | - Anastasiia Moraleva
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry RAS, 119997 Moscow, Russia
- Department of Applied Mathematics, MIREA-Russian Technological University, 119454 Moscow, Russia
| | - Kira Dobrochaeva
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry RAS, 119997 Moscow, Russia
| | - Diana Kovaleva
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry RAS, 119997 Moscow, Russia
| | - Maria Rubtsova
- Department of Chemistry, Lomonosov Moscow State University, 119991 Moscow, Russia
| | - Olga Dontsova
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry RAS, 119997 Moscow, Russia
- Department of Chemistry, Lomonosov Moscow State University, 119991 Moscow, Russia
| | - Yury Rubtsov
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry RAS, 119997 Moscow, Russia
- N.N.Blokhin National Medical Research Center of Oncology, Ministry of Health of the Russian Federation, 115478 Moscow, Russia
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2
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Dörner K, Ruggeri C, Zemp I, Kutay U. Ribosome biogenesis factors-from names to functions. EMBO J 2023; 42:e112699. [PMID: 36762427 PMCID: PMC10068337 DOI: 10.15252/embj.2022112699] [Citation(s) in RCA: 26] [Impact Index Per Article: 26.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2022] [Revised: 12/13/2022] [Accepted: 01/19/2023] [Indexed: 02/11/2023] Open
Abstract
The assembly of ribosomal subunits is a highly orchestrated process that involves a huge cohort of accessory factors. Most eukaryotic ribosome biogenesis factors were first identified by genetic screens and proteomic approaches of pre-ribosomal particles in Saccharomyces cerevisiae. Later, research on human ribosome synthesis not only demonstrated that the requirement for many of these factors is conserved in evolution, but also revealed the involvement of additional players, reflecting a more complex assembly pathway in mammalian cells. Yet, it remained a challenge for the field to assign a function to many of the identified factors and to reveal their molecular mode of action. Over the past decade, structural, biochemical, and cellular studies have largely filled this gap in knowledge and led to a detailed understanding of the molecular role that many of the players have during the stepwise process of ribosome maturation. Such detailed knowledge of the function of ribosome biogenesis factors will be key to further understand and better treat diseases linked to disturbed ribosome assembly, including ribosomopathies, as well as different types of cancer.
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Affiliation(s)
- Kerstin Dörner
- Department of Biology, Institute of Biochemistry, ETH Zurich, Zurich, Switzerland.,Molecular Life Sciences Ph.D. Program, Zurich, Switzerland
| | - Chiara Ruggeri
- Department of Biology, Institute of Biochemistry, ETH Zurich, Zurich, Switzerland.,RNA Biology Ph.D. Program, Zurich, Switzerland
| | - Ivo Zemp
- Department of Biology, Institute of Biochemistry, ETH Zurich, Zurich, Switzerland
| | - Ulrike Kutay
- Department of Biology, Institute of Biochemistry, ETH Zurich, Zurich, Switzerland
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Abstract
On January 2014 approximately 10,000 gallons of crude 4-Methylcyclohexanemethanol (MCHM) and propylene glycol phenol ether (PPH) were accidentally released into the Elk River, West Virginia, contaminating the tap water of around 300,000 residents. Crude MCHM is an industrial chemical used as flotation reagent to clean coal. At the time of the spill, MCHM's toxicological data were limited, an issue that has been addressed by different studies focused on understanding the immediate and long-term effects of MCHM on human health and the environment. Using S. cerevisiae as a model organism we study the effect of acute exposure to crude MCHM on metabolism. Yeasts were treated with MCHM 550 ppm in YPD for 30 minutes. Polar and lipid metabolites were extracted from cells by a chloroform-methanol-water mixture. The extracts were then analyzed by direct injection ESI-MS and by GC-MS. The metabolomics analysis was complemented with flux balance analysis simulations done with genome-scale metabolic network models (GSMNM) of MCHM treated vs non-treated control. We integrated the effect of MCHM on yeast gene expression from RNA-Seq data within these GSMNM. A total of 215 and 73 metabolites were identified by the ESI-MS and GC-MS procedures, respectively. From these 26 and 23 relevant metabolites were selected from ESI-MS and GC-MS respectively, for 49 unique compounds. MCHM induced amino acid accumulation, via its effects on amino acid metabolism, as well as a potential impairment of ribosome biogenesis. MCHM affects phospholipid biosynthesis, with a potential impact on the biophysical properties of yeast cellular membranes. The FBA simulations were able to reproduce the deleterious effect of MCHM on cellular growth and suggest that the effect of MCHM on ubiquinol:ferricytochrome c reductase reaction, caused by the under-expression of CYT1 gene, could be the driven force behind the observed effect on yeast metabolism and growth.
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Affiliation(s)
- Amaury Pupo
- Department of Biology, West Virginia University, Morgantown, West Virginia, United States of America
| | - Kang Mo Ku
- Division of Plant and Soil Sciences, West Virginia University, Morgantown, West Virginia, United States of America
- Department of Horticulture, College of Agriculture and Life Sciences, Chonnam National University, Gwangju, Republic of Korea
| | - Jennifer E. G. Gallagher
- Department of Biology, West Virginia University, Morgantown, West Virginia, United States of America
- * E-mail:
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Wu N, Liu B, Du H, Zhao S, Li Y, Cheng X, Wang S, Lin J, Zhou J, Qiu G, Wu Z, Zhang J. The Progress of CRISPR/Cas9-Mediated Gene Editing in Generating Mouse/Zebrafish Models of Human Skeletal Diseases. Comput Struct Biotechnol J 2019; 17:954-962. [PMID: 31360334 PMCID: PMC6639410 DOI: 10.1016/j.csbj.2019.06.006] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2019] [Revised: 05/28/2019] [Accepted: 06/11/2019] [Indexed: 12/18/2022] Open
Abstract
Genetic factors play a substantial role in the etiology of skeletal diseases, which involve 1) defects in skeletal development, including intramembranous ossification and endochondral ossification; 2) defects in skeletal metabolism, including late bone growth and bone remodeling; 3) defects in early developmental processes related to skeletal diseases, such as neural crest cell (NCC) and cilia functions; 4) disturbance of the cellular signaling pathways which potentially affect bone growth. Efficient and high-throughput genetic methods have enabled the exploration and verification of disease-causing genes and variants. Animal models including mouse and zebrafish have been extensively used in functional mechanism studies of causal genes and variants. The conventional approaches of generating mutant animal models include spontaneous mutagenesis, random integration, and targeted integration via mouse embryonic stem cells. These approaches are costly and time-consuming. Recent development and application of gene-editing tools, especially the CRISPR/Cas9 system, has significantly accelerated the process of gene-editing in diverse organisms. Here we review both mice and zebrafish models of human skeletal diseases generated by CRISPR/Cas9 system, and their contributions to deciphering the underpins of disease mechanisms.
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Affiliation(s)
- Nan Wu
- Department of Orthopedic Surgery, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing 100730, China
- Beijing Key Laboratory for Genetic Research of Skeletal Deformity, Beijing 100730, China
- Medical Research Center of Orthopedics, Chinese Academy of Medical Sciences, Beijing 100730, China
| | - Bowen Liu
- Department of Orthopedic Surgery, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing 100730, China
- Beijing Key Laboratory for Genetic Research of Skeletal Deformity, Beijing 100730, China
| | - Huakang Du
- Department of Orthopedic Surgery, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing 100730, China
- Beijing Key Laboratory for Genetic Research of Skeletal Deformity, Beijing 100730, China
| | - Sen Zhao
- Department of Orthopedic Surgery, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing 100730, China
- Beijing Key Laboratory for Genetic Research of Skeletal Deformity, Beijing 100730, China
| | - Yaqi Li
- Department of Orthopedic Surgery, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing 100730, China
- Beijing Key Laboratory for Genetic Research of Skeletal Deformity, Beijing 100730, China
| | - Xi Cheng
- Department of Orthopedic Surgery, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing 100730, China
- Beijing Key Laboratory for Genetic Research of Skeletal Deformity, Beijing 100730, China
| | - Shengru Wang
- Department of Orthopedic Surgery, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing 100730, China
- Beijing Key Laboratory for Genetic Research of Skeletal Deformity, Beijing 100730, China
| | - Jiachen Lin
- Department of Orthopedic Surgery, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing 100730, China
- Beijing Key Laboratory for Genetic Research of Skeletal Deformity, Beijing 100730, China
| | - Junde Zhou
- Beijing Key Laboratory for Genetic Research of Skeletal Deformity, Beijing 100730, China
| | | | - Guixing Qiu
- Department of Orthopedic Surgery, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing 100730, China
- Beijing Key Laboratory for Genetic Research of Skeletal Deformity, Beijing 100730, China
- Medical Research Center of Orthopedics, Chinese Academy of Medical Sciences, Beijing 100730, China
- Central Laboratory & Medical Research Center, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, China
| | - Zhihong Wu
- Beijing Key Laboratory for Genetic Research of Skeletal Deformity, Beijing 100730, China
- Central Laboratory & Medical Research Center, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, China
- Correspondence to: Z. Wu, Central Laboratory & Medical Research Center, Beijing Key Laboratory for Genetic Research of Skeletal Deformity, China.
| | - Jianguo Zhang
- Department of Orthopedic Surgery, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing 100730, China
- Beijing Key Laboratory for Genetic Research of Skeletal Deformity, Beijing 100730, China
- Medical Research Center of Orthopedics, Chinese Academy of Medical Sciences, Beijing 100730, China
- Correspondence to: J. Zhang, Department of Orthopedic Surgery, Beijing Key Laboratory for Genetic Research of Skeletal Deformity, Medical Research Center of Orthopedics, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, No. 1 Shuaifuyuan, Beijing 100730, China.
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5
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Chen J, Tan X, Wang Z, Liu Y, Zhou J, Rong X, Lu L, Li Y. The ribosome biogenesis protein Esf1 is essential for pharyngeal cartilage formation in zebrafish. FEBS J 2018; 285:3464-3484. [DOI: 10.1111/febs.14622] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2017] [Revised: 06/10/2018] [Accepted: 08/01/2018] [Indexed: 11/29/2022]
Affiliation(s)
- Jian‐Yang Chen
- Key Laboratory of Marine Drugs (Ocean University of China) Chinese Ministry of Education Qingdao China
- School of Medicine and Pharmacy Ocean University of China Qingdao China
- Laboratory for Marine Drugs and Biological Products Qingdao National Laboratory for Marine Science and Technology China
| | - Xungang Tan
- CAS Key Laboratory of Experimental Marine Biology Institute of Oceanology Chinese Academy of Sciences Qingdao China
| | - Zheng‐Hua Wang
- Key Laboratory of Marine Drugs (Ocean University of China) Chinese Ministry of Education Qingdao China
- School of Medicine and Pharmacy Ocean University of China Qingdao China
- Laboratory for Marine Drugs and Biological Products Qingdao National Laboratory for Marine Science and Technology China
- CAS Key Laboratory of Experimental Marine Biology Institute of Oceanology Chinese Academy of Sciences Qingdao China
| | - Yun‐Zhang Liu
- Key Laboratory of Marine Drugs (Ocean University of China) Chinese Ministry of Education Qingdao China
- School of Medicine and Pharmacy Ocean University of China Qingdao China
- Laboratory for Marine Drugs and Biological Products Qingdao National Laboratory for Marine Science and Technology China
| | - Jian‐Feng Zhou
- Key Laboratory of Marine Drugs (Ocean University of China) Chinese Ministry of Education Qingdao China
- School of Medicine and Pharmacy Ocean University of China Qingdao China
- Laboratory for Marine Drugs and Biological Products Qingdao National Laboratory for Marine Science and Technology China
| | - Xiao‐Zhi Rong
- Key Laboratory of Marine Drugs (Ocean University of China) Chinese Ministry of Education Qingdao China
- School of Medicine and Pharmacy Ocean University of China Qingdao China
- Laboratory for Marine Drugs and Biological Products Qingdao National Laboratory for Marine Science and Technology China
| | - Ling Lu
- Key Laboratory of Marine Drugs (Ocean University of China) Chinese Ministry of Education Qingdao China
- School of Medicine and Pharmacy Ocean University of China Qingdao China
- Laboratory for Marine Drugs and Biological Products Qingdao National Laboratory for Marine Science and Technology China
| | - Yun Li
- Key Laboratory of Marine Drugs (Ocean University of China) Chinese Ministry of Education Qingdao China
- School of Medicine and Pharmacy Ocean University of China Qingdao China
- Laboratory for Marine Drugs and Biological Products Qingdao National Laboratory for Marine Science and Technology China
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6
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Zhang L, Wu C, Cai G, Chen S, Ye K. Stepwise and dynamic assembly of the earliest precursors of small ribosomal subunits in yeast. Genes Dev 2016; 30:718-32. [PMID: 26980190 PMCID: PMC4803056 DOI: 10.1101/gad.274688.115] [Citation(s) in RCA: 88] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
In this study, Zhang et al. researched how the 90S preribosomal particle is cotranscriptionally assembled in yeast using a novel approach. They determined the assembly point of 65 proteins and the U3, U14, and snR30 snoRNAs, revealing a stepwise and dynamic assembly map, thereby advancing our understanding of small subunit biogenesis. The eukaryotic ribosomal RNA (rRNA) is associated cotranscriptionally with numerous factors into an enormous 90S preribosomal particle that conducts early processing of small ribosomal subunits. The assembly pathway and structure of the 90S particle is poorly understood. Here, we affinity-purified and analyzed the constituents of yeast 90S particles that were assembled on a series of plasmid-encoded 3′-truncated pre-18S RNAs. We determined the assembly point of 65 proteins and the U3, U14, and snR30 small nucleolar RNAs (snoRNAs), revealing a stepwise and dynamic assembly map. The 5′ external transcribed spacer (ETS) alone can nucleate a large complex. When the 18S rRNA is nearly complete, the 90S structure undergoes a dramatic reorganization, releasing U14, snR30, and 14 protein factors that bind earlier. We also identified a reference state of 90S that is fully assembled yet has not undergone 5′ETS processing. The assembly map present here provides a new framework to understand small subunit biogenesis.
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Affiliation(s)
- Liman Zhang
- National Institute of Biological Sciences, Beijing, Beijing 102206, China
| | - Chen Wu
- National Institute of Biological Sciences, Beijing, Beijing 102206, China; College of Biological Sciences, China Agricultural University, Beijing 100193, China; Key Laboratory of RNA Biology, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China; Beijing Key Laboratory of Noncoding RNA, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China
| | - Gaihong Cai
- National Institute of Biological Sciences, Beijing, Beijing 102206, China
| | - She Chen
- National Institute of Biological Sciences, Beijing, Beijing 102206, China
| | - Keqiong Ye
- Key Laboratory of RNA Biology, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China; Beijing Key Laboratory of Noncoding RNA, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China
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7
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Woolford JL, Baserga SJ. Ribosome biogenesis in the yeast Saccharomyces cerevisiae. Genetics 2013; 195:643-81. [PMID: 24190922 PMCID: PMC3813855 DOI: 10.1534/genetics.113.153197] [Citation(s) in RCA: 546] [Impact Index Per Article: 49.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2013] [Accepted: 08/26/2013] [Indexed: 01/09/2023] Open
Abstract
Ribosomes are highly conserved ribonucleoprotein nanomachines that translate information in the genome to create the proteome in all cells. In yeast these complex particles contain four RNAs (>5400 nucleotides) and 79 different proteins. During the past 25 years, studies in yeast have led the way to understanding how these molecules are assembled into ribosomes in vivo. Assembly begins with transcription of ribosomal RNA in the nucleolus, where the RNA then undergoes complex pathways of folding, coupled with nucleotide modification, removal of spacer sequences, and binding to ribosomal proteins. More than 200 assembly factors and 76 small nucleolar RNAs transiently associate with assembling ribosomes, to enable their accurate and efficient construction. Following export of preribosomes from the nucleus to the cytoplasm, they undergo final stages of maturation before entering the pool of functioning ribosomes. Elaborate mechanisms exist to monitor the formation of correct structural and functional neighborhoods within ribosomes and to destroy preribosomes that fail to assemble properly. Studies of yeast ribosome biogenesis provide useful models for ribosomopathies, diseases in humans that result from failure to properly assemble ribosomes.
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Affiliation(s)
- John L. Woolford
- Department of Biological Sciences, Center for Nucleic Acids Science and Technology, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213
| | - Susan J. Baserga
- Molecular Biophysics and Biochemistry, Genetics and Therapeutic Radiology, Yale University, New Haven, Connecticut 06520-8024
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8
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Phipps KR, Charette JM, Baserga SJ. The small subunit processome in ribosome biogenesis—progress and prospects. WILEY INTERDISCIPLINARY REVIEWS-RNA 2012; 2:1-21. [PMID: 21318072 DOI: 10.1002/wrna.57] [Citation(s) in RCA: 129] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The small subunit (SSU) processome is a 2.2-MDa ribonucleoprotein complex involved in the processing, assembly, and maturation of the SSU of eukaryotic ribosomes. The identities of many of the factors involved in SSU biogenesis have been elucidated over the past 40 years. However, as our understanding increases, so do the number of questions about the nature of this complicated process. Cataloging the components is the first step toward understanding the molecular workings of a system. This review will focus on how identifying components of ribosome biogenesis has led to the knowledge of how these factors, protein and RNA alike, associate with one another into subcomplexes, with a concentration on the small ribosomal subunit. We will also explore how this knowledge of subcomplex assembly has informed our understanding of the workings of the ribosome synthesis system as a whole.
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Affiliation(s)
- Kathleen R Phipps
- Department of Molecular Biophysics and Biochemistry, Yale University School of Medicine, New Haven, CT, USA
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9
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LeBron C, Pal P, Brait M, Dasgupta S, Guerrero-Preston R, Looijenga LH, Kowalski J, Netto G, Hoque MO. Genome-wide analysis of genetic alterations in testicular primary seminoma using high resolution single nucleotide polymorphism arrays. Genomics 2011; 97:341-9. [DOI: 10.1016/j.ygeno.2011.02.011] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2010] [Revised: 01/11/2011] [Accepted: 02/25/2011] [Indexed: 11/26/2022]
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10
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Mrd1p is required for release of base-paired U3 snoRNA within the preribosomal complex. Mol Cell Biol 2009; 29:5763-74. [PMID: 19704003 DOI: 10.1128/mcb.00428-09] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
In eukaryotes, ribosomes are made from precursor rRNA (pre-rRNA) and ribosomal proteins in a maturation process that requires a large number of snoRNPs and processing factors. A fundamental problem is how the coordinated and productive folding of the pre-rRNA and assembly of successive pre-rRNA-protein complexes is achieved cotranscriptionally. The conserved protein Mrd1p, which contains five RNA binding domains (RBDs), is essential for processing events leading to small ribosomal subunit synthesis. We show that full function of Mrd1p requires all five RBDs and that the RBDs are functionally distinct and needed during different steps in processing. Mrd1p mutations trap U3 snoRNA in pre-rRNP complexes both in base-paired and non-base-paired interactions. A single essential RBD, RBD5, is involved in both types of interactions, but its conserved RNP1 motif is not needed for releasing the base-paired interactions. RBD5 is also required for the late pre-rRNP compaction preceding A(2) cleavage. Our results suggest that Mrd1p modulates successive conformational rearrangements within the pre-rRNP that influence snoRNA-pre-rRNA contacts and couple U3 snoRNA-pre-rRNA remodeling and late steps in pre-rRNP compaction that are essential for cleavage at A(0) to A(2). Mrd1p therefore coordinates key events in biosynthesis of small ribosome subunits.
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11
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Remodeling yeast gene transcription by activating the Ty1 long terminal repeat retrotransposon under severe adenine deficiency. Mol Cell Biol 2008; 28:5543-54. [PMID: 18591253 DOI: 10.1128/mcb.00416-08] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The Ty1 long terminal repeat (LTR) retrotransposon of Saccharomyces cerevisiae is a powerful model to understand the activation of transposable elements by stress and their impact on genome expression. We previously discovered that Ty1 transcription is activated under conditions of severe adenine starvation. The mechanism of activation is independent of the Bas1 transcriptional activator of the de novo AMP biosynthesis pathway and probably involves chromatin remodeling at the Ty1 promoter. Here, we show that the 5' LTR has a weak transcriptional activity and is sufficient for the activation by severe adenine starvation. Furthermore, we demonstrate that Ty1 insertions that bring Ty1 promoter sequences into the vicinity of a reporter gene confer adenine starvation regulation on it. We provide evidence that similar coactivation of genes adjacent to Ty1 sequences occurs naturally in the yeast genome, indicating that Ty1 insertions can mediate transcriptional control of yeast gene expression under conditions of severe adenine starvation. Finally, the transcription pattern of genes adjacent to Ty1 insertions suggests that severe adenine starvation facilitates the initiation of transcription at alternative sites, partly located in the 5' LTR. We propose that Ty1-driven transcription of coding and noncoding sequences could regulate yeast gene expression in response to stress.
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12
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Abstract
Synthesis of rRNA in eukaryotes involves the action of a large population of snoRNA-protein complexes (snoRNPs), which create modified nucleotides and participate in cleavage of pre-rRNA. The snoRNPs mediate these functions through direct base pairing, in many cases through long complementary sequences. This feature suggests that RNA helicases may be involved in the binding and release of snoRNPs from pre-rRNA. In this study, we determined that the DEAD box helicase Has1p, a nucleolar protein required for the production of 18S rRNA, copurifies with the snR30/U17 processing snoRNP but is also present with other snoRNPs. Blocking Has1p expression causes a substantial increase in snoRNPs associated with 60S-90S preribosomal RNP complexes, including the U3 and U14 processing snoRNPs and several modifying snoRNPs examined. Cosedimentation persisted even after deproteinization. This effect was not observed with depletion of two nonhelicase proteins, Esf1p and Dim2p, that are also required for 18S rRNA production. Point mutations in ATPase and helicase motifs of Has1p block U14 release from pre-rRNA. Surprisingly, depletion of Has1p causes a reduction in the level of free U6 snRNP. The results indicate that the Has1p helicase is required for snoRNA release from pre-rRNA and production of the U6 snRNP.
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Affiliation(s)
- Xue-Hai Liang
- Department of Biochemistry and Molecular Biology, Lederle Graduate Research Center, University of Massachusetts, Amherst, MA 01003, USA
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13
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Bleichert F, Granneman S, Osheim YN, Beyer AL, Baserga SJ. The PINc domain protein Utp24, a putative nuclease, is required for the early cleavage steps in 18S rRNA maturation. Proc Natl Acad Sci U S A 2006; 103:9464-9. [PMID: 16769905 PMCID: PMC1480430 DOI: 10.1073/pnas.0603673103] [Citation(s) in RCA: 75] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Ribosome biogenesis is a complex process that requires >150 transacting factors, many of which form macromolecular assemblies as big and complex as the ribosome itself. One of those complexes, the SSU processome, is required for pre-18S rRNA maturation. Although many of its components have been identified, the endonucleases that cleave the pre-18S rRNA have remained mysterious. Here we examine the role of four previously uncharacterized PINc domain proteins, which are predicted to function as nucleases, in yeast ribosome biogenesis. We also included Utp23, a protein homologous to the PINc domain protein Utp24, in our analysis. Our results demonstrate that Utp23 and Utp24 are essential nucleolar proteins and previously undescribed components of the SSU processome. In that sense, both Utp23 and Utp24 are required for the first three cleavage steps in 18S rRNA maturation. In addition, single-point mutations in the conserved putative active site of Utp24 but not Utp23 abrogate its function in ribosome biogenesis. Our results suggest that Utp24 might be the elusive endonuclease that cleaves the pre-rRNA at sites A(1) and/or A(2.).
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Affiliation(s)
| | | | - Yvonne N. Osheim
- Department of Microbiology, University of Virginia Health System, Charlottesville, VA 22908
| | - Ann L. Beyer
- Department of Microbiology, University of Virginia Health System, Charlottesville, VA 22908
| | - Susan J. Baserga
- Departments of *Genetics
- Molecular Biophysics and Biochemistry, and
- Therapeutic Radiology, Yale University School of Medicine, New Haven, CT 06520; and
- To whom correspondence should be addressed. E-mail:
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14
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Hoang T, Peng WT, Vanrobays E, Krogan N, Hiley S, Beyer AL, Osheim YN, Greenblatt J, Hughes TR, Lafontaine DLJ. Esf2p, a U3-associated factor required for small-subunit processome assembly and compaction. Mol Cell Biol 2005; 25:5523-34. [PMID: 15964808 PMCID: PMC1156982 DOI: 10.1128/mcb.25.13.5523-5534.2005] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Esf2p is the Saccharomyces cerevisiae homolog of mouse ABT1, a protein previously identified as a putative partner of the TATA-element binding protein. However, large-scale studies have indicated that Esf2p is primarily localized to the nucleolus and that it physically associates with pre-rRNA processing factors. Here, we show that Esf2p-depleted cells are defective for pre-rRNA processing at the early nucleolar cleavage sites A0 through A2 and consequently are inhibited for 18S rRNA synthesis. Esf2p was stably associated with the 5' external transcribed spacer (ETS) and the box C+D snoRNA U3, as well as additional box C+D snoRNAs and proteins enriched within the small-subunit (SSU) processome/90S preribosomes. Esf2p colocalized on glycerol gradients with 90S preribosomes and slower migrating particles containing 5' ETS fragments. Strikingly, upon Esf2p depletion, chromatin spreads revealed that SSU processome assembly and compaction are inhibited and glycerol gradient analysis showed that U3 remains associated within 90S preribosomes. This suggests that in the absence of proper SSU processome assembly, early pre-rRNA processing is inhibited and U3 is not properly released from the 35S pre-rRNAs. The identification of ABT1 in a large-scale analysis of the human nucleolar proteome indicates that its role may also be conserved in mammals.
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MESH Headings
- Cell Nucleolus/genetics
- Cell Nucleolus/metabolism
- Chromatin/genetics
- Chromatin/metabolism
- Nuclear Proteins
- RNA Processing, Post-Transcriptional
- RNA, Fungal/biosynthesis
- RNA, Fungal/chemistry
- RNA, Fungal/genetics
- RNA, Fungal/metabolism
- RNA, Ribosomal, 18S/biosynthesis
- RNA, Ribosomal, 18S/chemistry
- RNA, Ribosomal, 18S/genetics
- RNA, Small Nuclear/chemistry
- RNA, Small Nuclear/genetics
- RNA, Small Nuclear/metabolism
- RNA, Small Nucleolar/chemistry
- RNA, Small Nucleolar/genetics
- RNA, Small Nucleolar/metabolism
- Ribonucleoproteins, Small Nucleolar/chemistry
- Ribonucleoproteins, Small Nucleolar/genetics
- Ribonucleoproteins, Small Nucleolar/metabolism
- Saccharomyces cerevisiae/cytology
- Saccharomyces cerevisiae/genetics
- Saccharomyces cerevisiae/metabolism
- Saccharomyces cerevisiae Proteins/metabolism
- Transcription, Genetic
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Affiliation(s)
- Tran Hoang
- Fonds National de la Recherche Scientifique, Université Libre de Bruxelles, Institut de Biologie et de Médecine Moléculaires, Charleroi-Gosselies, Belgium
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15
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Zhou XJ, Kao MCJ, Huang H, Wong A, Nunez-Iglesias J, Primig M, Aparicio OM, Finch CE, Morgan TE, Wong WH. Functional annotation and network reconstruction through cross-platform integration of microarray data. Nat Biotechnol 2005; 23:238-43. [PMID: 15654329 DOI: 10.1038/nbt1058] [Citation(s) in RCA: 107] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2004] [Accepted: 11/01/2004] [Indexed: 01/01/2023]
Abstract
The rapid accumulation of microarray data translates into a need for methods to effectively integrate data generated with different platforms. Here we introduce an approach, 2(nd)-order expression analysis, that addresses this challenge by first extracting expression patterns as meta-information from each data set (1(st)-order expression analysis) and then analyzing them across multiple data sets. Using yeast as a model system, we demonstrate two distinct advantages of our approach: we can identify genes of the same function yet without coexpression patterns and we can elucidate the cooperativities between transcription factors for regulatory network reconstruction by overcoming a key obstacle, namely the quantification of activities of transcription factors. Experiments reported in the literature and performed in our lab support a significant number of our predictions.
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16
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Current awareness on yeast. Yeast 2004; 21:1133-40. [PMID: 15529464 DOI: 10.1002/yea.1095] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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