Discovery and Characterization of a Cellular Potent Positive Allosteric Modulator of the Polycomb Repressive Complex 1 Chromodomain, CBX7

Kelsey N Lamb; Daniel Bsteh; Sarah N Dishman; Hagar F Moussa; Huitao Fan; Jacob I Stuckey; Jacqueline L Norris; Stephanie H Cholensky; Dongxu Li; Jingkui Wang; Cari Sagum; Benjamin Z Stanton; Mark T Bedford; Kenneth H Pearce; Terry P Kenakin; Dmitri B Kireev; Gang Greg Wang; Lindsey I James; Oliver Bell; Stephen V Frye

doi:10.1016/j.chembiol.2019.07.013

Discovery and Characterization of a Cellular Potent Positive Allosteric Modulator of the Polycomb Repressive Complex 1 Chromodomain, CBX7

Cell Chem Biol. 2019 Oct 17;26(10):1365-1379.e22. doi: 10.1016/j.chembiol.2019.07.013. Epub 2019 Aug 15.

Authors

Kelsey N Lamb¹, Daniel Bsteh², Sarah N Dishman¹, Hagar F Moussa³, Huitao Fan⁴, Jacob I Stuckey¹, Jacqueline L Norris¹, Stephanie H Cholensky¹, Dongxu Li⁴, Jingkui Wang⁵, Cari Sagum⁶, Benjamin Z Stanton⁷, Mark T Bedford⁶, Kenneth H Pearce¹, Terry P Kenakin⁸, Dmitri B Kireev¹, Gang Greg Wang⁴, Lindsey I James¹, Oliver Bell⁹, Stephen V Frye¹⁰

Affiliations

¹ Center for Integrative Chemical Biology and Drug Discovery, Division of Chemical Biology and Medicinal Chemistry, UNC Eshelman School of Pharmacy, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA.
² Institute of Molecular Biotechnology of the Austrian Academy of Sciences (IMBA), Vienna Biocenter (VBC), Dr. Bohr-Gasse 3, 1030 Vienna, Austria; Department of Biochemistry and Molecular Medicine and Norris Comprehensive Cancer Center, Keck School of Medicine of the University of Southern California, Los Angeles, CA 90033, USA.
³ Institute of Molecular Biotechnology of the Austrian Academy of Sciences (IMBA), Vienna Biocenter (VBC), Dr. Bohr-Gasse 3, 1030 Vienna, Austria.
⁴ Lineberger Comprehensive Cancer Center, UNC School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA; Department of Biochemistry and Biophysics, UNC School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA.
⁵ Research Institute of Molecular Pathology (IMP), Vienna Biocenter (VBC), Campus-Vienna-Biocenter 1, 1030 Vienna, Austria.
⁶ Department of Epigenetics and Molecular Carcinogenesis, University of Texas MD Anderson Cancer Center, Smithville, TX 78957, USA.
⁷ Division of Preclinical Innovation, National Center for Advancing Translational Sciences NIH, Rockville, MD 20850, USA.
⁸ Department of Pharmacology, UNC School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA.
⁹ Institute of Molecular Biotechnology of the Austrian Academy of Sciences (IMBA), Vienna Biocenter (VBC), Dr. Bohr-Gasse 3, 1030 Vienna, Austria; Department of Biochemistry and Molecular Medicine and Norris Comprehensive Cancer Center, Keck School of Medicine of the University of Southern California, Los Angeles, CA 90033, USA. Electronic address: oliver.bell@med.usc.edu.
¹⁰ Center for Integrative Chemical Biology and Drug Discovery, Division of Chemical Biology and Medicinal Chemistry, UNC Eshelman School of Pharmacy, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA; Lineberger Comprehensive Cancer Center, UNC School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA. Electronic address: svfrye@email.unc.edu.

Abstract

Polycomb-directed repression of gene expression is frequently misregulated in human diseases. A quantitative and target-specific cellular assay was utilized to discover the first potent positive allosteric modulator (PAM) peptidomimetic, UNC4976, of nucleic acid binding by CBX7, a chromodomain methyl-lysine reader of Polycomb repressive complex 1. The PAM activity of UNC4976 resulted in enhanced efficacy across three orthogonal cellular assays by simultaneously antagonizing H3K27me3-specific recruitment of CBX7 to target genes while increasing non-specific binding to DNA and RNA. PAM activity thereby reequilibrates PRC1 away from H3K27me3 target regions. Together, our discovery and characterization of UNC4976 not only revealed the most cellularly potent PRC1-specific chemical probe to date, but also uncovers a potential mechanism of Polycomb regulation with implications for non-histone lysine methylated interaction partners.

Keywords: allosterism; chromatin; chromodomain; methyl-lysine reader; polycomb; positive allosteric modulator.

Publication types

Research Support, N.I.H., Extramural
Research Support, Non-U.S. Gov't

MeSH terms

Allosteric Regulation / drug effects
Animals
Drug Discovery*
HEK293 Cells
HeLa Cells
Humans
Mice
Peptidomimetics / chemistry
Peptidomimetics / pharmacology*
Polycomb Repressive Complex 1 / metabolism*

Substances

CBX7 protein, human
Peptidomimetics
Polycomb Repressive Complex 1

Abstract

Publication types

MeSH terms

Substances

Grants and funding