Identification of histone peptide binding specificity and small-molecule ligands for the TRIM33α and TRIM33β bromodomains

DOI: 10.1021/acschembio.2c00266

Authors: Angelina R. Sekirnik (University of Oxford) , Jessica K. Reynolds (University of Oxford) , Larissa See (University of Oxford) , Joseph P. Bluck (University of Oxford) , Amy R. Scorah (University of Oxford) , Cynthia Tallant (Structural Genomics Consortium, University of Oxford, U.K.) , Bernadette Lee (University of Oxford) , Katarzyna B. Leszczynska (University of Oxford) , Rachel L. Grimley (Pfizer Ltd) , R. Ian Storer (Pfizer Ltd) , Marta Malattia (Evotec (UK) Ltd) , Sara Crespillo (Evotec (UK) Ltd) , Sofia Caria (Evotec (UK) Ltd) , Stephanie Duclos (Evotec (UK) Ltd) , Ester M. Hammond (University of Oxford) , Stefan Knapp (Structural Genomics Consortium, Goethe University) , Garrett M. Morris (University of Oxford) , Fernanda Duarte (University of Oxford) , Philip C. Biggin (University of Oxford) , Stuart J. Conway (University of Oxford)
Co-authored by industrial partner: Yes

Type: Journal Paper
Journal: Acs Chemical Biology

State: Published (Approved)
Published: September 2022

Abstract: TRIM33 is a member of the tripartite motif (TRIM) family of proteins, some of which possess E3 ligase activity and are involved in the ubiquitin-dependent degradation of proteins. Four of the TRIM family proteins, TRIM24 (TIF1α), TRIM28 (TIF1β), TRIM33 (TIF1γ) and TRIM66, contain C-terminal plant homeodomain (PHD) and bromodomain (BRD) modules, which bind to methylated lysine (KMen) and acetylated lysine (KAc), respectively. Here we investigate the differences between the two isoforms of TRIM33, TRIM33α and TRIM33β, using structural and biophysical approaches. We show that the N1039 residue, which is equivalent to N140 in BRD4(1) and which is conserved in most BRDs, has a different orientation in each isoform. In TRIM33β, this residue coordinates KAc, but this is not the case in TRIM33α. Despite these differences, both isoforms show similar affinities for H31–27K18Ac, and bind preferentially to H31–27K9Me3K18Ac. We used this information to develop an AlphaScreen assay, with which we have identified four new ligands for the TRIM33 PHD-BRD cassette. These findings provide fundamental new information regarding which histone marks are recognized by both isoforms of TRIM33 and suggest starting points for the development of chemical probes to investigate the cellular function of TRIM33.

Journal Keywords: Assays; Cancer; Genetics; Ligands; Peptides and proteins

Subject Areas: Biology and Bio-materials, Chemistry


Instruments: I03-Macromolecular Crystallography

Added On: 03/10/2022 11:27

Discipline Tags:

Non-Communicable Diseases Health & Wellbeing Cancer Biochemistry Chemistry Structural biology Biophysics Life Sciences & Biotech

Technical Tags:

Diffraction Macromolecular Crystallography (MX)