Protein Interaction Screen on Peptide Matrix (PRISMA) reveals interaction footprints and PTM-dependent interactome of intrinsically disordered C/EBPβ

Gunnar Dittmar, Daniel Perez Hernandez, Elisabeth Kowenz-Leutz, Marieluise Kirchner, Günther Kahlert, Radoslaw Wesolowski, Katharina Baum, Maria Knoblich, Maria Hofstätter, Arnaud Muller, Jana Wolf, Ulf Reimer (+1 others)
2019 iScience  
CCAAT enhancer-binding protein beta (C/EBPβ) is a pioneer transcription factor that specifies cell differentiation. C/EBPβ is intrinsically unstructured, a molecular feature common to many proteins involved in signal processing and epigenetics. The structure of C/EBPβ differs depending on alternative translation initiation and multiple post-translational modifications (PTM). Mutation of distinct PTM sites in C/EBPβ alters protein interactions and cell differentiation, suggesting that a C/EBPβ
more » ... M indexing code determines epigenetic outcomes. Herein, we systematically explored the interactome of C/EBPβ using an array technique based on spot-synthesized C/EBPβ-derived linear tiling peptides with and without PTM, combined with mass spectrometric proteomic analysis of protein interactions. We identified interaction footprints of ∼1,300 proteins in nuclear extracts, many with chromatin modifying, chromatin remodeling, and RNA processing functions. The results suggest that C/EBPβ acts as a multi-tasking molecular switchboard, integrating signal-dependent modifications and structural plasticity to orchestrate interactions with numerous protein complexes directing cell fate and function.
doi:10.1016/j.isci.2019.02.026 pmid:30884312 pmcid:PMC6424098 fatcat:zrlhzheaqbb2felj54e6f2mxl4