Journal Article DKFZ-2026-00633

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Inhibition of p300/CREBBP catalytic activity drives context-dependent transcriptional activation in AML.

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2026
American Society of Hematology Washington, DC

Blood nn, nn () [10.1182/blood.2025031924]
 GO

Abstract: The lysine acetyltransferase (KAT) activity of p300/CREBBP has traditionally been linked to transcriptional activation. This has been attributed largely to acetylation of histone residues such as H3K27ac, a defining hallmark of active regulatory elements. Here we show that, in acute myeloid leukemia (AML), inhibition of p300/CREBBP catalysis can paradoxically increase transcription. We combined time-resolved dynamics of nascent and total transcription with chromatin binding dynamics of p300/CREBBP and their associated TFs/co-regulators (inferred from chromatin pull-down proteomics, acetyl-proteomics and motif enrichment) to uncover mechanisms of transcriptional rewiring after p300/CREBBP catalytic inhibition. In parallel, we dissected the functional contribution of individual p300/CREBBP acetyl-interactome members to KAT inhibition using genome-wide CRISPR-Cas9 dropout and focused Perturb-seq screens. Together, these approaches revealed that KAT inhibition paradoxically retains p300/CREBBP and promotes cooperative TF assembly and increased H3K27 acetylation at a subset of regulatory elements. The effect was most pronounced at IRF motif-enriched loci, including interferon-stimulated genes (ISGs), where KAT inhibition triggered p300/CREBBP accumulation and enhanced combinatorial TF binding, enabling recruitment of the ISG activator STAT1. Consequently, ISG loci were converted into transcriptionally active states that induced cell-cycle arrest, differentiation and apoptosis. Therapeutically, combining KAT inhibition with interferon-alpha augmented ISG expression, synergistically drove AML cell death in vitro and significantly extended survival in both AML xenografts and murine models. These findings refine our understanding of p300/CREBBP KAT activity, demonstrating that cooperative TF assembly can reconfigure p300/CREBBP-containing complexes under catalytic inhibition to induce transcription, with translational implications for reprogramming interferon-driven programs through catalytic inhibition in AML and beyond.

Classification:

Note: #DKTKZFB26# / epub

Contributing Institute(s):
  1. DKTK Koordinierungsstelle Frankfurt (FM01)
  2. DKTK FM Proteomics Facility (FM03)
Research Program(s):
  1. 899 - ohne Topic (POF4-899) (POF4-899)

Appears in the scientific report 2026
Database coverage:
Medline ; OpenAccess ; BIOSIS Previews ; Biological Abstracts ; Clarivate Analytics Master Journal List ; Current Contents - Clinical Medicine ; Current Contents - Life Sciences ; Ebsco Academic Search ; Essential Science Indicators ; IF >= 20 ; JCR ; PubMed Central ; SCOPUS ; Science Citation Index Expanded ; Web of Science Core Collection
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 Record created 2026-03-19, last modified 2026-05-08


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