The TRIM33 Bromodomain Recognizes Histone Lysine Lactylation. ACS Chem Biol 2024 Dec 20;19(12):2418-2428
Date
11/18/2024Pubmed ID
39556662Pubmed Central ID
PMC11706526DOI
10.1021/acschembio.4c00248Scopus ID
2-s2.0-85209707761 (requires institutional sign-in at Scopus site) 1 CitationAbstract
Histone lysine lactylation (Kla) regulates inflammatory gene expression in activated macrophages and mediates the polarization of inflammatory (M1) to reparative (M2) macrophages. However, the molecular mechanisms and key protein players involved in Kla-mediated transcriptional changes are unknown. As Kla is structurally similar to lysine acetylation (Kac), which is bound by bromodomains, we hypothesized that bromodomain-containing proteins bind histone Kla. Here, we screened 28 recombinantly expressed bromodomains for binding to histone Kla peptides via AlphaScreen assays. TRIM33 was the sole bromodomain tested that bound histone Kla peptides. TRIM33 attenuates inflammatory genes during late-stage macrophage activation; thus, TRIM33 provides a potential link between histone Kla and macrophage polarization. Orthogonal biophysical techniques, including isothermal titration calorimetry and protein-detected nuclear magnetic resonance, confirmed the submicromolar binding affinity of the TRIM33 bromodomain to both Kla and Kac histone post-translational modifications. Sequence alignments of human bromodomains revealed a unique glutamic acid residue within the TRIM33 binding pocket that we found confers TRIM33 specificity for binding Kla compared with other bromodomains. Molecular modeling of interactions of Kla with the TRIM33 bromodomain binding pocket and site-directed mutagenesis of glutamic acid confirmed the critical role of this residue in the selective recognition of Kla by TRIM33. Collectively, our findings implicate TRIM33, a bromodomain-containing protein, as a novel reader of histone Kla, potentially bridging the gap between histone Kla and macrophage polarization. This study enhances our understanding of the regulatory role of histone Kla in macrophage-mediated inflammation and offers insights into the underlying structural and biophysical mechanisms.
Author List
Nuñez R, Sidlowski PFW, Steen EA, Wynia-Smith SL, Sprague DJ, Keyes RF, Smith BCAuthors
Robert Keyes PhD Research Scientist II in the Biochemistry department at Medical College of WisconsinBrian C. Smith PhD Associate Professor in the Biochemistry department at Medical College of Wisconsin
Sarah L. Wynia Smith Research Scientist II in the Biochemistry department at Medical College of Wisconsin
MESH terms used to index this publication - Major topics in bold
AcetylationAmino Acid Sequence
Histones
Humans
Lysine
Macrophages
Protein Binding
Protein Domains
Protein Processing, Post-Translational
Transcription Factors
