Enzymatic Characterization of In Vitro Activity of RNA Methyltransferase PCIF1 on DNA

  • Biochemistry. 2022 May 23;61(11):1005-1013. doi: 10.1021/acs.biochem.2c00134.
Dan Yu  1 ,  Jujun Zhou  1 ,  Qin Chen  1 ,  Tao Wu  2 ,  Robert M Blumenthal  3 ,  Xing Zhang  1 ,  Xiaodong Cheng  1
Affiliations
  • 1. Department of Epigenetics and Molecular Carcinogenesis, University of Texas MD Anderson Cancer Center, Houston, Texas 77030, United States.
  • 2. Department of Molecular & Human Genetics, Baylor College of Medicine, Houston, Texas 77030, United States.
  • 3. Department of Medical Microbiology and Immunology, and Program in Bioinformatics, The University of Toledo College of Medicine and Life Sciences, Toledo, Ohio 43614, United States.
PMID: 35605980 DOI: 10.1021/acs.biochem.2c00134
Abstract

PCIF1 and FTO are a pair of human mRNA cap-specific modification Enzymes that have opposing activities. PCIF1 adds a methyl group to the N6-position of 2'O-methyladenosine (Am), generating N6, 2'O-dimethyladenosine (m6Am), when Am is the cap-proximal nucleotide. FTO removes the N6-methyl group from m6Am. In addition, FTO has a demethylase activity on a broad spectrum of various RNA substrates, as well as on DNA N6-methyldeoxyadenosine (m6dA). While the existence of m6dA in mammalian DNA remains controversial, we show here that PCIF1 has significant methylation activity on single stranded DNA deoxyadenosine, double stranded RNA/DNA hybrids, and double stranded DNA, though with lower catalytic efficiency than that on its preferred RNA substrate. PCIF1 has activities in the order ssRNA > RNA/DNA hybrid > ssDNA > dsDNA. We discuss the implications of PCIF1 generation, and FTO removal, of DNA adenine methylation.

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