Our studies suggest that BRD4 plays a critical role in muscle fiber-type regulation, yet the molecular mechanisms by which BRD4 cooperates with MEF2 to control muscle gene expression remain incompletely understood. To identify potential bridging factors that facilitate BRD4-MEF2 interaction, unbiased TurboID-based proximity labeling was employed to map BRD4- and MEF2-associated proteins. Comparative analysis of the BRD4- and MEF2C-TurboID proximity interactomes revealed that CHD4, a core component of the NuRD chromatin-remodeling complex, was identified as a prominent candidate. Functional protein association networks analysis indicated that these shared proteins are related to chromatin organization and transcriptional regulation.