@article{93e323f59c024ae59e33a2592c848e40,
title = "The inactive Dnmt3b3 isoform preferentially enhances Dnmt3b-mediated DNA methylation",
abstract = "The de novo DNA methyltransferases Dnmt3a and Dnmt3b play crucial roles in developmental and cellular processes. Their enzymatic activities are stimulated by a regulatory protein Dnmt3L (Dnmt3-like) in vitro. However, genetic evidence indicates that Dnmt3L functions predominantly as a regulator of Dnmt3a in germ cells. How Dnmt3a and Dnmt3b activities are regulated during embryonic development and in somatic cells remains largely unknown. Here we show that Dnmt3b3, a catalytically inactive Dnmt3b isoform expressed in differentiated cells, positively regulates de novo methylation by Dnmt3a and Dnmt3b with a preference for Dnmt3b. Dnmt3b3 is equally potent as Dnmt3L in stimulating the activities of Dnmt3a2 and Dnmt3b2 in vitro. Like Dnmt3L, Dnmt3b3 forms a complex with Dnmt3a2 with a stoichiometry of 2:2. However, rescue experiments in Dnmt3a/3b/3l tripleknockout (TKO) mouse embryonic stem cells (mESCs) reveal that Dnmt3b3 prefers Dnmt3b2 over Dnmt3a2 in remethylating genomic sequences. Dnmt3a2, an active isoform that lacks the N-terminal uncharacterized region of Dnmt3a1 including a nuclear localization signal, has very low activity in TKO mESCs, indicating that an accessory protein is absolutely required for its function. Our results suggest that Dnmt3b3 and perhaps similar Dnmt3b isoforms facilitate de novo DNA methylation during embryonic development and in somatic cells.",
keywords = "DNA cytosine methylation, De novo methylation, Dnmt3a, Dnmt3b, Dnmt3b3",
author = "Yang Zeng and Ren Ren and Gundeep Kaur and Swanand Hardikar and Zhengzhou Ying and Lance Babcock and Esha Gupta and Xing Zhang and Taiping Chen and Xiaodong Cheng",
note = "Funding Information: We thank Dr. Yiwei Liu for his initial work in preparing expression constructs, protein purifications, and activity assays; Dr. Zhongwu Zhou for his participation of EM examination; Dr. Anup Kumar Singh, Dr. Jiameng Dan, Dr. Nicolas Veland, Dr. Tewfik Hamidi, and Dr. Bigang Liu for discussions and technical assistance; and Ms. Yu Cao for technical assistance. We thank Dr. B.V. Venkatar Prasad and Dr. Soni Kaundal at Baylor College of Medicine for help in sedimentation velocity analytical ultracentrifugation experiments. This work is supported by the U.S. National Institutes of Health (NIH; R35GM134744 to X.C. and R01AI1214030A1 to T.C.), the Cancer Prevention and Research Institute of Texas (CPRIT; RR160029 to X.C., who is a CPRIT Scholar in Cancer Research), a Thomas Endowment fellowship (to Y.Z.), and a Sam and Freda Davis Fund fellowship (to Z.Y.). NIH P30GM124169-01 and the Department of Energy{\textquoteright}s Office of Biological and Environmental Research Integrated Diffraction Analysis Technology Program support SAXS data collection at SIBYLS. CPRIT RP190602 partially supports the CryoEM/Cry-oET Core at Baylor College of Medicine. CPRIT RP170628 partially supports confocal microscopy. Funding Information: We thank Dr. Yiwei Liu for his initial work in preparing expression constructs, protein purifications, and activity assays; Dr. Zhongwu Zhou for his participation of EM examination; Dr. Anup Kumar Singh, Dr. Jiameng Dan, Dr. Nicolas Veland, Dr. Tewfik Hamidi, and Dr. Bigang Liu for discussions and technical assistance; and Ms. Yu Cao for technical assistance. We thank Dr. B.V. Venkatar Prasad and Dr. Soni Kaundal at Baylor College of Medicine for help in sedimentation velocity analytical ultracentrifugation experiments. This work is supported by the U.S. National Institutes of Health (NIH; R35GM134744 to X.C. and R01AI1214030A1 to T.C.), the Cancer Prevention and Research Institute of Texas (CPRIT; RR160029 to X.C., who is a CPRIT Scholar in Cancer Research), a Thomas Endowment fellowship (to Y.Z.), and a Sam and Freda Davis Fund fellowship (to Z.Y.). NIH P30GM124169-01 and the Department of Energy's Office of Biological and Environmental Research Integrated Diffraction Analysis Technology Program support SAXS data collection at SIBYLS. CPRIT RP190602 partially supports the CryoEM/CryoET Core at Baylor College of Medicine. CPRIT RP170628 partially supports confocal microscopy. Publisher Copyright: {\textcopyright} 2020 Zeng et al.",
year = "2020",
month = nov,
day = "1",
doi = "10.1101/gad.341925.120",
language = "English (US)",
volume = "34",
pages = "1546--1558",
journal = "Genes and Development",
issn = "0890-9369",
publisher = "Cold Spring Harbor Laboratory Press",
}