BRAT1 associates with INTS11/INTS9 heterodimer to regulate key neurodevelopmental genes

Abstract

AbstractIntegrator is a multi-subunits protein complex involved in regulation of gene expression. Several Integrator subunits have been found to be mutated in human neurodevelopmental disorders, suggesting a key role for the complex in the development of nervous system.BRAT1is similarly linked with neurodegenerative diseases and neurodevelopmental disorders such as rigidity and multifocal-seizure syndrome. Here, we show that INTS11 and INTS9 subunits of Integrator complex interact with BRAT1 and form a trimeric complex in human HEK293T cells as well as in pluripotent human embryonal carcinoma cell line (NT2). We find thatBRAT1depletion disrupts the differentiation of NT2 cells into astrocytes and neural cells. Loss ofBRAT1results in inability to activate many neuronal genes that are targets of REST, a neuronal silencer. We identified BRAT1 and INTS11 co-occupying the promoter region of these genes and pinpoint a role for BRAT1 in recruiting INTS11 to their promoters. Disease-causing mutations inBRAT1diminish its association with INTS11/INTS9, linking the manifestation of disease phenotypes with a defect in transcriptional activation of key neuronal genes by BRAT1/INTS11/INTS9 complex.HighlightsIntegrator subunits INTS9 and INTS11 tightly interact with BRAT1Depletion ofBRAT1causes a dramatic delay in human neural differentiationBRAT1 and INTS11 module targets the promoters of neural marker genes and co-regulates their expression. The recruitment of INTS11 to these sites is BRAT1-dependent.Pathogenic E522K mutation inBRAT1disrupts its interaction with INTS11/INTS9 heterodimer.