SETDB1 Triple Tudor Domain Ligand, (R,R)-59, Promotes Methylation of Akt1 in Cells

Uguen, M.; Deng, Y.; Li, F.; Shell, D. J.; Norris-Drouin, J. L.; Stashko, M. A.; Ackloo, S.; Arrowsmith, C. H.; James, L. I.; Liu, P.; Pearce, K. H.; Frye, S. V.

doi:10.1101/2023.05.10.539986

bioRxiv · 10.1101/2023.05.10.539986

SETDB1 Triple Tudor Domain Ligand, (R,R)-59, Promotes Methylation of Akt1 in Cells

Uguen, M.·Deng, Y.·Li, F.·Shell, D. J.·Norris-Drouin, J. L.·Stashko, M. A.·Ackloo, S.·Arrowsmith, C. H.·James, L. I.·Liu, P.·Pearce, K. H.·Frye, S. V.

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Abstract

Increased expression and hyperactivation of the methyltransferase SETDB1 are commonly observed in cancer and central nervous system disorders. However, there are currently no reported SETDB1-specific methyltransferase inhibitors in the literature, suggesting this is a challenging target. Here, we disclose that the previously reported small-molecule ligand for SETDB1s Triple Tudor Domain, (R,R)-59, is unexpectedly able to increase SETDB1 methyltransferase activity both in vitro and in cells. Specifically, (R,R)-59 promotes in vitro SETDB1-mediated methylation of lysine 64 of the protein kinase Akt1. Treatment with (R,R)-59 also increased Akt1 threonine 308 phosphorylation and activation, a known consequence of Akt1 methylation, resulting in stimulated cell proliferation in a dose-dependent manner. (R,R)-59 is the first SETDB1 small-molecule positive activator for the methyltransferase activity of this protein. Mechanism of action studies show that full-length SETDB1 is required for significant in vitro methylation of an Akt1-K64 peptide, and that this activity is stimulated by (R,R)-59 primarily through an increase in catalytic activity rather than a change in SAM binding. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=63 SRC="FIGDIR/small/539986v1_ufig1.gif" ALT="Figure 1"> View larger version (15K): org.highwire.dtl.DTLVardef@5f4022org.highwire.dtl.DTLVardef@16ba47borg.highwire.dtl.DTLVardef@1fb8b0borg.highwire.dtl.DTLVardef@16595bc_HPS_FORMAT_FIGEXP M_FIG C_FIG

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Uguen, M., Deng, Y., Li, F., Shell, D. J., Norris-Drouin, J. L., Stashko, M. A., Ackloo, S., Arrowsmith, C. H., James, L. I., Liu, P., Pearce, K. H., Frye, S. V.. 2023-05-10. SETDB1 Triple Tudor Domain Ligand, (R,R)-59, Promotes Methylation of Akt1 in Cells. https://doi.org/10.1101/2023.05.10.539986

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