Figure 3.

Model for the role of SUVH in heterochromatin formation and maintain. Two self‐reinforcing loops between maintenance of histone and DNA methylation are displayed. (a) SUVH4, SUVH5, and SUVH6 bind to methylated DNA and the H3K9me2 modification recruits CMT3 for DNA methylation. The methylated DNA further recruits SUVH4, SUVH5 and SUVH6. (b) SUVH2 and SUVH9 bind to methylated DNA at RdDM loci and the H3K9me2 modification recruits DDR complex at the loci. DDR leads Pol V to RdDM loci, producing noncoding RNAs to interact with 24 nt‐siRNAs bound by AGO4, which recruits DRM2 for DNA methylation. The methylated DNA is further bound by SUVH2 and SUVH9. AGO4, ARGONAUTE4; DRM2, DOMAINS REARRANGED METHYLTRANSFERASE 2; DDR complex, DMS3, DRD1, and RDM1; RdDM, RNA‐directed DNA methylation; SUVH, Suv homologs