CFP1 has a zinc finger domain (CXXC) which binds to non-methylated CpG rich DNA both in vitro and in vivo. CpG islands involve promoters of most genes in vertebrate genomes. CFP1 is a component of the mammalian SETD1 histone H3K4 methyltransferase complex. Hence, it directs local chromatin structure and is essential for vertebrate development in different organisms (1).
Research indicates that CFP1 restricts SETD1 to euchromatin (2). In another domain, the protein may be recruiting DNMT in times of transition from euchromatin to heterochromatin (3). Additionally, embryonic stem cells deficient in CFP1 show decreased levels of cytosine methylation and increased levels of H3K4 methylation which indicate reduced levels of heterochromatin in the cells (4).
A model of how CFP1 binds to DNA through its CXXC is shown with annotations that highlight key features.
PDB: 3QMB; (1) doi:10.1038/ncomms1237; (2) doi:10.1111/j.1742-4658.2009.07475.x; (3) doi:10.1089/dna.2007.0714; (4) doi:10.1371/journal.pone.0113745
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