CBP-IDRs regulate acetylation and gene expression [CUT&Run]

Intrinsically disordered regions (IDRs) have emerged as crucial regulators of protein function, allowing proteins to sense and respond to their environment. Creb binding protein (CBP) and EP300 (p300) are transcription coactivators that regulate gene expression in multicellular organisms, following their recruitment to cis-regulatory elements. CBP and p300 contain large IDRs, however little is known about how these different IDRs work together to regulate CBP function. Here, we show that CBP-IDRs cooperate to control different aspects of CBP behaviour in the nucleus, by regulating the properties of fluid-like condensates formed by endogenous CBP. We show how IDRs with different sequence properties make unique contributions to CBP behaviour by establishing a balance between positive and negative regulation of CBP condensates. These conflicting interactions are functionally important, shaping CBPs response to factors such as lysine acetylation, that influence condensate formation. When disrupted, regulatory CBP-IDRs change how CBP interacts with chromatin, alter patterns of CBP-dependent histone acetylation and change gene expression. Together, our work highlights how IDRs with different sequences, spatially segregated in the same protein, can cooperate to shape protein function. Overall design: Cleavage Under Targets and Release Using Nuclease (CUT&RUN) for doxycycline inducible GFP epitope-tagged Crebbp binding protein (CBP) in HEK293T cells. Doxycycline was added to induce GFP expression while not altering overall levels of tagged and untagged CBP. Control ChIP-seq for endogenous CBP was done in parental HEK293T cells stably expressing Tet3G transactivator protein. The same system was used to generate datasets for H3K27ac CUT&RUN and total RNAseq, following induction of CBP-GFP expression. Please note that the processed data files generated from both replicates are linked to the corresponding Rep1 sample records.