title: Ectopic gene expression and organogenesis in Arabidopsis mutants missing BRU1 required for genome maintenance.
abstract: Chromatin reconstitution after DNA replication and repair is essential for the inheritance of epigenetic information, but mechanisms underlying such a process are still poorly understood. Previously, we proposed that Arabidopsis BRU1 functions to ensure the chromatin reconstitution. Loss-of-function mutants of BRU1 are hypersensitive to genotoxic stresses and cause release of transcriptional gene silencing of heterochromatic genes. In this study, we show that BRU1 also plays roles in gene regulation in euchromatic regions. bru1 mutations caused sporadic ectopic expression of genes, including those that encode master regulators of developmental programs such as stem cell maintenance and embryogenesis. bru1 mutants exhibited adventitious organogenesis, probably due to the misexpression of such developmental regulators. The key regulatory genes misregulated in bru1 alleles were often targets of PcG SET-domain proteins, although the overlap between the bru1-misregulated and PcG SET-domain-regulated genes was limited at a genome-wide level. Surprisingly, a considerable fraction of the genes activated in bru1 were located in several subchromosomal regions ranging from 174 to 944 kb in size. Our results suggest that BRU1 has a function related to the stability of subchromosomal gene regulation in the euchromatic regions, in addition to the maintenance of chromatin states coupled with heritable epigenetic marks.
authors.affiliation: Bioscience and Biotechnology Center, Nagoya University, Chikusa, Nagoya 464-8601, Japan.
authors.forename: Yusuke
authors.initials: Y
authors.lastname: Ohno
authors.forename: Jarunya
authors.initials: J
authors.lastname: Narangajavana
authors.forename: Akiko
authors.initials: A
authors.lastname: Yamamoto
authors.forename: Tsukaho
authors.initials: T
authors.lastname: Hattori
authors.forename: Yasuaki
authors.initials: Y
authors.lastname: Kagaya
authors.forename: Jerzy
authors.initials: J
authors.lastname: Paszkowski
authors.forename: Wilhelm
authors.initials: W
authors.lastname: Gruissem
authors.forename: Lars
authors.initials: L
authors.lastname: Hennig
authors.forename: Shin
authors.initials: S
authors.lastname: Takeda
mesh_terms: D017360:Arabidopsis / Q000196:embryology / Q000235:genetics* / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000235:genetics* / Q000378:metabolism; D002467:Cell Nucleus / Q000378:metabolism; D002874:Chromosome Mapping; D032461:Chromosomes, Plant; D020869:Gene Expression Profiling; D018507:Gene Expression Regulation, Developmental; D018506:Gene Expression Regulation, Plant; D018745:Genome, Plant; D009154:Mutation / Q000235:genetics*; D038081:Organogenesis / Q000235:genetics; D063146:Polycomb-Group Proteins; D012097:Repressor Proteins / Q000378:metabolism; D014157:Transcription Factors / Q000235:genetics; D002868:Chromosomal Proteins, Non-Histone
chemical_list: D029681:Arabidopsis Proteins; D063146:Polycomb-Group Proteins; D012097:Repressor Proteins; D014157:Transcription Factors; C502726:FUSCA3 protein, Arabidopsis; C487787:AT3G18730 protein, Arabidopsis; D002868:Chromosomal Proteins, Non-Histone