title: Non-CG methylation patterns shape the epigenetic landscape in Arabidopsis.
abstract: DNA methylation occurs in CG and non-CG sequence contexts. Non-CG methylation is abundant in plants and is mediated by CHROMOMETHYLASE (CMT) and DOMAINS REARRANGED METHYLTRANSFERASE (DRM) proteins; however, its roles remain poorly understood. Here we characterize the roles of non-CG methylation in Arabidopsis thaliana. We show that a poorly characterized methyltransferase, CMT2, is a functional methyltransferase in vitro and in vivo. CMT2 preferentially binds histone H3 Lys9 (H3K9) dimethylation and methylates non-CG cytosines that are regulated by H3K9 methylation. We revealed the contributions and redundancies between each non-CG methyltransferase in DNA methylation patterning and in regulating transcription. We also demonstrate extensive dependencies of small-RNA accumulation and H3K9 methylation patterning on non-CG methylation, suggesting self-reinforcing mechanisms between these epigenetic factors. The results suggest that non-CG methylation patterns are critical in shaping the landscapes of histone modification and small noncoding RNA.
authors: Department of Molecular, Cell and Developmental Biology, University of California, Los Angeles, Los Angeles, California, USA.
authors: Hume
authors: H
authors: Stroud
authors: Department of Molecular, Cell and Developmental Biology, University of California, Los Angeles, Los Angeles, California, USA.
authors: Truman
authors: T
authors: Do
authors: Structural Biology Program, Memorial Sloan-Kettering Cancer Center, New York, New York, USA.
authors: Jiamu
authors: J
authors: Du
authors: 1] Department of Molecular, Cell and Developmental Biology, University of California, Los Angeles, Los Angeles, California, USA. [2].
authors: Xuehua
authors: X
authors: Zhong
authors: 1] Department of Molecular, Cell and Developmental Biology, University of California, Los Angeles, Los Angeles, California, USA. [2] Eli and Edythe Broad Center of Regenerative Medicine and Stem Cell Research, University of California, Los Angeles, Los Angeles, California, USA. [3] Howard Hughes Medical Institute, University of California, Los Angeles, Los Angeles, California, USA.
authors: Suhua
authors: S
authors: Feng
authors: Department of Molecular, Cell and Developmental Biology, University of California, Los Angeles, Los Angeles, California, USA.
authors: Lianna
authors: L
authors: Johnson
authors: Structural Biology Program, Memorial Sloan-Kettering Cancer Center, New York, New York, USA.
authors: Dinshaw J
authors: DJ
authors: Patel
authors: 1] Department of Molecular, Cell and Developmental Biology, University of California, Los Angeles, Los Angeles, California, USA. [2] Eli and Edythe Broad Center of Regenerative Medicine and Stem Cell Research, University of California, Los Angeles, Los Angeles, California, USA. [3] Howard Hughes Medical Institute, University of California, Los Angeles, Los Angeles, California, USA.
authors: Steven E
authors: SE
authors: Jacobsen
mesh_terms: D017360:Arabidopsis / Q000235:genetics*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism* / Q000502:physiology; D019175:DNA Methylation; D018744:DNA, Plant; D044127:Epigenesis, Genetic
chemical_list: D029681:Arabidopsis Proteins; D018744:DNA, Plant