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IPMK physically binds to the SWI/SNF complex and modulates BRG1 occupancy

ABSTRACT: Inositol polyphosphate multikinase (IPMK), a key enzyme in the inositol polyphosphate (IP) metabolism, is a pleiotropic signaling factor involved in major biological events, including transcriptional control. In the yeast, IPMK and its IP products promote the activity of the chromatin-remodeling complex SWI/SNF, which plays a critical role in gene expression by regulating chromatin accessibility. However, the direct link between IPMK and chromatin remodelers remains unclear, raising a question on how IPMK contributes to the transcriptional regulation in mammals. By employing unbiased screening approaches and in vivo/in vitro immunoprecipitations, here we demonstrated that mammalian IPMK physically interacts with the SWI/SNF complex by directly binding to SMARCB1, BRG1, and SMARCC1. Furthermore, we identified the specific domains required for the IPMK-SMARCB1 binding. Notably, using the CUT&RUN and ATAC-seq assays, we discovered that IPMK co-localizes with BRG1 and regulates BRG1 localization as well as BRG1-mediated chromatin accessibility in a genome-wide manner in mouse embryonic stem cells. Finally, our mRNA-seq analyses revealed that IPMK and SMARCB1 regulate the expression of a common gene set, validating a functional link between IPMK and the SWI/SNF complex. Together, these findings show that IPMK regulates promoter-targeting of the SWI/SNF complex and thereby contributes to SWI/SNF-meditated chromatin accessibility, transcription, and differentiation.

ORGANISM(S): Mus musculus

PROVIDER: GSE158525 | GEO | 2022/05/10

REPOSITORIES: GEO

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