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Genetic analysis implicates a molecular chaperone complex in regulating epigenetic silencing of methylated genomic regions
Author(s) -
Feng Zhengyan,
Zhan Xiangqiang,
Pang Jia,
Liu Xue,
Zhang Huiming,
Lang Zhaobo,
Zhu JianKang
Publication year - 2021
Publication title -
journal of integrative plant biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.734
H-Index - 83
eISSN - 1744-7909
pISSN - 1672-9072
DOI - 10.1111/jipb.13155
Subject(s) - biology , dna methylation , gene silencing , epigenetics , genetics , mutant , methylation , microbiology and biotechnology , dna , gene , gene expression
DNA cytosine methylation confers stable epigenetic silencing in plants and many animals. However, the mechanisms underlying DNA methylation‐mediated genomic silencing are not fully understood. We conducted a forward genetic screen for cellular factors required for the silencing of a heavily methylated p35S:NPTII transgene in the Arabidopsis thaliana rdm1‐1 mutant background, which led to the identification of a Hsp20 family protein, RDS1 ( rd m1‐1 s uppressor 1). Loss‐of‐function mutations in RDS1 released the silencing of the p35S::NPTII transgene in rdm1‐1 mutant plants, without changing the DNA methylation state of the transgene. Protein interaction analyses suggest that RDS1 exists in a protein complex consisting of the methyl‐DNA binding domain proteins MBD5 and MBD6, two other Hsp20 family proteins, RDS2 and IDM3, a Hsp40/DNAJ family protein, and a Hsp70 family protein. Like rds1 mutations, mutations in RDS2 , MBD5 , or MBD6 release the silencing of the transgene in the rdm1 mutant background. Our results suggest that Hsp20, Hsp40, and Hsp70 proteins may form a complex that is recruited to some genomic regions with DNA methylation by methyl‐DNA binding proteins to regulate the state of silencing of these regions.