Recombination Regulation by Transcription-Induced Cohesin Dissociation in rDNA Repeats

• Published in: Science (American Association for the Advancement of Science) Vol. 309; no. 5740; pp. 1581 - 1584
• Main Authors: Kobayashi, Takehiko, Ganley, Austen R. D
• Format: Journal Article
• Language: English
• Published: Washington, DC American Association for the Advancement of Science 02.09.2005; The American Association for the Advancement of Science
• Subjects: Analysis; Biological and medical sciences; Cell Cycle Proteins - metabolism; Chromatids; Chromosomal Proteins, Non-Histone; Chromosome mapping; Chromosomes; Coding; Cohesins; Deoxyribonucleic acid; dissociation; DNA; DNA, Ribosomal - genetics; DNA-binding proteins; DNA-Binding Proteins - metabolism; Fundamental and applied biological sciences. Psychology; Fungal Proteins - metabolism; Gels; Gene Amplification; Gene Dosage; Genes; Genetic recombination; Models, Genetic; Molecular and cellular biology; Molecular genetics; Motor Vehicles; Nuclear Proteins - metabolism; Polymerase chain reaction; Professional cooking; Promoter Regions, Genetic; Proteins; Recombination, Genetic; repetitive sequences; Ribosomal DNA; ribosomal RNA; RNA; RNA Polymerase II - genetics; Saccharomyces cerevisiae; Transcription, Genetic; Transcription. Transcription factor. Splicing. Rna processing; Transcriptional regulatory elements; yeasts; Gene silencing; Recombination; Regulation(control); Transcription; Ribosomal RNA; DNA binding protein; Mechanism
• ISSN: 0036-8075; 1095-9203
• DOI: 10.1126/science.1116102

Organisms maintain ribosomal RNA gene repeats (rDNA) at stable copy numbers by recombination; the loss of repeats results in gene amplification. Here we report a mechanism of amplification regulation. We show that amplification is dependent on transcription from a noncoding bidirectional promoter (E-pro) within the rDNA spacer. E-pro transcription stimulates the dissociation of cohesin, a DNA binding protein complex that suppresses sister-chromatid-based changes in rDNA copy number. This transcription is regulated by the silencing gene, SIR2, and by copy number. Transcription-induced cohesin dissociation may be a general mechanism of recombination regulation.