PMID: 23292653 , Related PDB id: 4FL6

Authors:

James LI, Barsyte-Lovejoy D, Zhong N, Krichevsky L, Korboukh VK, Herold JM, MacNevin CJ, Norris JL, Sagum CA, Tempel W, Marcon E, Guo H, Gao C, Huang XP, Duan S, Emili A, Greenblatt JF, Kireev DB, Jin J, Janzen WP, Brown PJ, Bedford MT, Arrowsmith CH, Frye SV

Title:

Discovery of a chemical probe for the L3MBTL3 methyllysine reader domain.

Journal:

Nat Chem Biol. 2013 Mar;9(3):184-91. doi: 10.1038/nchembio.1157. Epub 2013 Jan 6.

Abstract:

We describe the discovery of UNC1215, a potent and selective chemical probe for the methyllysine (Kme) reading function of L3MBTL3, a member of the malignant brain tumor (MBT) family of chromatin-interacting transcriptional repressors. UNC1215 binds L3MBTL3 with a K(d) of 120 nM, competitively displacing mono- or dimethyllysine-containing peptides, and is greater than 50-fold more potent toward L3MBTL3 than other members of the MBT family while also demonstrating selectivity against more than 200 other reader domains examined. X-ray crystallography identified a unique 2:2 polyvalent mode of interaction between UNC1215 and L3MBTL3. In cells, UNC1215 is nontoxic and directly binds L3MBTL3 via the Kme-binding pocket of the MBT domains. UNC1215 increases the cellular mobility of GFP-L3MBTL3 fusion proteins, and point mutants that disrupt the Kme-binding function of GFP-L3MBTL3 phenocopy the effects of UNC1215 on localization. Finally, UNC1215 was used to reveal a new Kme-dependent interaction of L3MBTL3 with BCLAF1, a protein implicated in DNA damage repair and apoptosis.