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5-18-2018 Comparative biochemical analysis of UHRF proteins reveals molecular mechanisms that uncouple UHRF2 from DNA methylation maintenance Robert M. Vaughan Van Andel Research Institute
Bradley M. Dickson Van Andel Research Institute
Evan M. Cornett Van Andel Research Institute
Joseph S. Harrison University of the Pacific, [email protected]
Brian Kuhlman University of North Carolina at Chapel Hill
FSeoe nelloxtw pa thige fors aaddndition addal aitutionhorsal works at: https://scholarlycommons.pacific.edu/cop-facarticles Part of the Biochemistry, Biophysics, and Structural Biology Commons, and the Chemistry Commons
Recommended Citation Vaughan, R. M., Dickson, B. M., Cornett, E. M., Harrison, J. S., Kuhlman, B., & Rothbart, S. B. (2018). Comparative biochemical analysis of UHRF proteins reveals molecular mechanisms that uncouple UHRF2 from DNA methylation maintenance. Nucleic Acids Research, 46(9), 4405–4416. DOI: 10.1093/nar/gky151 https://scholarlycommons.pacific.edu/cop-facarticles/568
This Article is brought to you for free and open access by the All Faculty Scholarship at Scholarly Commons. It has been accepted for inclusion in College of the Pacific aF culty Articles by an authorized administrator of Scholarly Commons. For more information, please contact [email protected]. Authors Robert M. Vaughan, Bradley M. Dickson, Evan M. Cornett, Joseph S. Harrison, Brian Kuhlman, and Scott .B Rothbart
This article is available at Scholarly Commons: https://scholarlycommons.pacific.edu/cop-facarticles/568 Published online 28 February 2018 Nucleic Acids Research, 2018, Vol. 46, No. 9 4405–4416 doi: 10.1093/nar/gky151 Comparative biochemical analysis of UHRF proteins reveals molecular mechanisms that uncouple UHRF2 from DNA methylation maintenance
Robert M. Vaughan1, Bradley M. Dickson1, Evan M. Cornett1, Joseph S. Harrison2,3, Downloaded from https://academic.oup.com/nar/article-abstract/46/9/4405/4913573 by University of the Pacific user on 20 November 2018 Brian Kuhlman2,3 and Scott B. Rothbart1,*
1Center for Epigenetics, Van Andel Research Institute, Grand Rapids, MI 49503, USA, 2Department of Biochemistry and Biophysics, University of North Carolina at Chapel Hill, NC 27599, USA and 3Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, NC 27599, USA
Received December 21, 2017; Revised February 13, 2018; Editorial Decision February 15, 2018; Accepted February 21, 2018
ABSTRACT INTRODUCTION UHRF1 is a histone- and DNA-binding E3 ubiq- A major challenge of modern biology has been to determine uitin ligase that functions with DNMT1 to main- how DNA-templated processes like transcription, replica- tain mammalian DNA methylation. UHRF1 facilitates tion and repair are temporally and spatially regulated in the DNMT1 recruitment to replicating chromatin through context of chromatin. Histone post-translational modifica- a coordinated mechanism involving histone and tions (PTMs) and DNA methylation have emerged as key regulators of chromatin accessibility, interaction, and sig- DNA recognition and histone ubiquitination. UHRF2 naling. Breakthroughs in our understanding of chromatin shares structural homology with UHRF1, but sur- regulatory mechanisms have been made through the charac- prisingly lacks functional redundancy to facilitate terization of protein machineries that write, erase, and read DNA methylation maintenance. Molecular mecha- these epigenetic marks. The faithful mitotic inheritance of nisms uncoupling UHRF2 from DNA methylation DNA methylation patterns is essential for mammalian de- maintenance are poorly defined. Through compre- velopment and is well studied for its key roles in the sta- hensive and comparative biochemical analysis of re- ble transcriptional silencing of genes and transposable el- combinant human UHRF1 and UHRF2 reader and ements, genomic imprinting, and X-chromosome inactiva- writer activities, we reveal conserved modes of hi- tion (1). DNA methylation patterns are established by de stone PTM recognition but divergent DNA binding novo methyltransferases during early embryonic develop- properties. While UHRF1 and UHRF2 diverge in their ment and are maintained through somatic cell divisions by the maintenance methyltransferase DNMT1 (DNA methyl- affinities toward hemi-methylated DNA, we surpris- transferase 1), which has increased catalytic activity toward ingly show that both hemi-methylated and hemi- hemi-methylated DNA (He5mC) (2–4). The E3 ubiquitin hydroxymethylated DNA oligonucleotides stimulate ligase UHRF1 (ubiquitin-like, containing PHD and RING UHRF2 ubiquitin ligase activity toward histone H3 finger domains 1) is now appreciated as a key regulator peptide substrates. This is the first example of an of DNMT1-mediated DNA methylation maintenance. Ge- E3 ligase allosterically regulated by DNA hydrox- netic and biochemical studies revealed that UHRF1 plays ymethylation. However, UHRF2 is not a productive a central role in DNMT1-directed DNA methylation main- histone E3 ligase toward purified mononucleosomes, tenance during DNA replication (5,6). Deletion of Uhrf1 (or Np95) in mice is embryonic lethal, and stem cells de- suggesting UHRF2 has an intra-domain architecture −/− distinct from UHRF1 that is conformationally con- rived from Uhrf1 embryos (and also from human cells strained when bound to chromatin. Collectively, our depleted of UHRF1) show a dramatic loss in DNA methy- lation, impaired maintenance of higher-order chromatin studies reveal that uncoupling of UHRF2 from the structure, and spurious transcription of otherwise silenced DNA methylation maintenance program is linked to repetitive DNA elements (6–9). differences in the molecular readout of chromatin The DNA methylation maintenance function of UHRF1 signatures that connect UHRF1 to ubiquitination of is dependent on its ability to bind chromatin, where it fa- histone H3. cilitates ubiquitination of histone H3 at lysines 18 and 23 (H3K18ub and H3K23ub, respectively), a proposed dock-
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