| Histone methylation controls telomerase-independent telomere lengthening in cells undergoing dedifferentiation. | |
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MedLine Citation:
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PMID: 17448460 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
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Cellular dedifferentiation underlies topical issues in biology such as regeneration and nuclear cloning and has common features in plants and animals. In plants, this process characterizes the transition of differentiated leaf cells to protoplasts (plant cells devoid of cell walls) and is accompanied by global chromatin reorganization associated with reprogramming of gene expression. A screen for mutants defective in proliferation and callus formation identified kyp-2-a mutant in the KRYPTONITE (KYP)/SUVH4 gene encoding a histone H3 lysine 9 (H3K9) methyltransferase. Analysis of telomere length revealed stochastic telomerase-independent lengthening of telomeres in wild type but not in kyp-2 protoplasts. In kyp-2 mutant, telomeric repeats were no longer associated with dimethylated H3K9. The Arabidopsis telomerase reverse transcriptase (tert) mutant displayed accelerated proliferation despite its short telomeres, though it also showed accelerated cell death. Microarray analysis uncovered several components of the ubiquitin proteolytic system, which are downregulated in kyp-2 compared to wild-type protoplasts. Thus, our results suggest that histone methylation activity is required for the establishment/maintenance of the dedifferentiated state and/or reentry into the cell cycle, at least partly, through activation of genes whose products are involved in the ubiquitin proteolytic pathway. In addition, our results illuminate the complexity of cellular dedifferentiation, particularly the occurrence of DNA recombination that can lead to genome instability. |
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Authors:
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Gideon Grafi; Hagit Ben-Meir; Yigal Avivi; Maya Moshe; Yardena Dahan; Assaf Zemach |
Publication Detail:
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Type: Journal Article; Research Support, Non-U.S. Gov't Date: 2007-03-23 |
Journal Detail:
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Title: Developmental biology Volume: 306 ISSN: 0012-1606 ISO Abbreviation: Dev. Biol. Publication Date: 2007 Jun |
Date Detail:
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Created Date: 2007-06-11 Completed Date: 2007-08-01 Revised Date: 2008-11-21 |
Medline Journal Info:
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Nlm Unique ID: 0372762 Medline TA: Dev Biol Country: United States |
Other Details:
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Languages: eng Pagination: 838-46 Citation Subset: IM |
Affiliation:
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Albert Katz Department of Dryland Biotechnologies, Jacob Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Sede Boqer Campus 84990, Israel. ggrafi@bgu.ac.il |
Export Citation:
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| MeSH Terms | |
Descriptor/Qualifier:
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Arabidopsis
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genetics*,
physiology* Arabidopsis Proteins / genetics, physiology Cell Cycle Cell Differentiation Chromatin / metabolism Chromatin Immunoprecipitation DNA Methylation Gene Expression Regulation, Plant* Histones / chemistry*, metabolism Mutation Oligonucleotide Array Sequence Analysis Plant Physiological Phenomena Protoplasts / metabolism Telomere / ultrastructure* Ubiquitin / metabolism |
| Chemical | |
Reg. No./Substance:
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0/Arabidopsis Proteins; 0/Chromatin; 0/Histones; 0/Ubiquitin |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
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