scholarly journals Arabidopsis MAS2, an Essential Gene That Encodes a Homolog of Animal NF-κ B Activating Protein, Is Involved in 45S Ribosomal DNA Silencing

2015 ◽  
Vol 27 (7) ◽  
pp. 1999-2015 ◽  
Author(s):  
Ana Belén Sánchez-García ◽  
Verónica Aguilera ◽  
Rosa Micol-Ponce ◽  
Sara Jover-Gil ◽  
María Rosa Ponce
Keyword(s):  
Ribosomal Dna ◽  
Essential Gene ◽  
Dna Silencing

scholarly journals Y chromosome mediates ribosomal DNA silencing and modulates the chromatin state in Drosophila

2012 ◽  
Vol 109 (25) ◽  
pp. 9941-9946 ◽  
Author(s):  
J. Zhou ◽  
T. B. Sackton ◽  
L. Martinsen ◽  
B. Lemos ◽  
T. H. Eickbush ◽  
...  
Keyword(s):  
Y Chromosome ◽  
Ribosomal Dna ◽  
Chromatin State ◽  
Dna Silencing

scholarly journals The Epigenetic Pathways to Ribosomal DNA Silencing

2016 ◽  
Vol 80 (3) ◽  
pp. 545-563 ◽  
Author(s):  
Rakesh Srivastava ◽  
Rashmi Srivastava ◽  
Seong Hoon Ahn
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Chromosome Segregation ◽  
Ribosomal Dna ◽  
Genome Stability ◽  
Cellular Aging ◽  
Content Type ◽  
Eukaryotic Chromatin ◽  
Normal Life Span ◽  
Protein Components ◽  
Dna Silencing

SUMMARYHeterochromatin is the transcriptionally repressed portion of eukaryotic chromatin that maintains a condensed appearance throughout the cell cycle. At sites of ribosomal DNA (rDNA) heterochromatin, epigenetic states contribute to gene silencing and genome stability, which are required for proper chromosome segregation and a normal life span. Here, we focus on recent advances in the epigenetic regulation of rDNA silencing inSaccharomyces cerevisiaeand in mammals, including regulation by several histone modifications and several protein components associated with the inner nuclear membrane within the nucleolus. Finally, we discuss the perturbations of rDNA epigenetic pathways in regulating cellular aging and in causing various types of diseases.

scholarly journals A Genetic Screen for Ribosomal DNA Silencing Defects Identifies Multiple DNA Replication and Chromatin-Modulating Factors

1999 ◽  
Vol 19 (4) ◽  
pp. 3184-3197 ◽  
Author(s):  
Jeffrey S. Smith ◽  
Emerita Caputo ◽  
Jef D. Boeke
Keyword(s):  
Dna Replication ◽  
Ribosomal Dna ◽  
Chromatin Structure ◽  
Position Effect ◽  
Reporter Genes ◽  
Rdna Locus ◽  
Genetic Screen ◽  
Regulator Genes ◽  
Dna Silencing

ABSTRACT Transcriptional silencing in Saccharomyces cerevisiaeoccurs at several genetic loci, including the ribosomal DNA (rDNA). Silencing at telomeres (telomere position effect [TPE]) and the cryptic mating-type loci (HML and HMR) depends on the silent information regulator genes, SIR1,SIR2, SIR3, and SIR4. However, silencing of polymerase II-transcribed reporter genes integrated within the rDNA locus (rDNA silencing) requires only SIR2. The mechanism of rDNA silencing is therefore distinct from TPE andHM silencing. Few genes other than SIR2 have so far been linked to the rDNA silencing process. To identify additional non-Sir factors that affect rDNA silencing, we performed a genetic screen designed to isolate mutations which alter the expression of reporter genes integrated within the rDNA. We isolated two classes of mutants: those with a loss of rDNA silencing (lrs) phenotype and those with an increased rDNA silencing (irs) phenotype. Using transposon mutagenesis,lrs mutants were found in 11 different genes, andirs mutants were found in 22 different genes. Surprisingly, we did not isolate any genes involved in rRNA transcription. Instead, multiple genes associated with DNA replication and modulation of chromatin structure were isolated. We describe these two gene classes, and two previously uncharacterized genes, LRS4 andIRS4. Further characterization of the lrs andirs mutants revealed that many had alterations in rDNA chromatin structure. Several lrs mutants, including those in the cdc17 and rfc1 genes, caused lengthened telomeres, consistent with the hypothesis that telomere length modulates rDNA silencing. Mutations in the HDB (RPD3) histone deacetylase complex paradoxically increased rDNA silencing by aSIR2-dependent, SIR3-independent mechanism. Mutations in rpd3 also restored mating competence selectively to sir3Δ MATα strains, suggesting restoration of silencing at HMR in a sir3mutant background.

scholarly journals N-alpha-terminal Acetylation of Histone H4 Regulates Arginine Methylation and Ribosomal DNA Silencing

PLoS Genetics ◽  
2013 ◽  
Vol 9 (9) ◽  
pp. e1003805 ◽  
Author(s):  
Vassia Schiza ◽  
Diego Molina-Serrano ◽  
Dimitris Kyriakou ◽  
Antonia Hadjiantoniou ◽  
Antonis Kirmizis
Keyword(s):  
Ribosomal Dna ◽  
Arginine Methylation ◽  
Histone H4 ◽  
Dna Silencing
Sign in / Sign up

Export Citation Format

Share Document