BRAT1 links Integrator and defective RNA processing with neurodegeneration

Area of Science:

• Molecular Biology
• Neuroscience
• Genetics

Background:

• Mutations in BRAT1 (BRCA1-associated ATM activator 1) are linked to neurodevelopmental and neurodegenerative disorders.
• The molecular mechanisms driving these BRAT1-related diseases are not well understood.

Purpose of the Study:

• To investigate the molecular function of BRAT1 and its role in neurodegenerative disease pathology.
• To elucidate the interaction of BRAT1 with the Integrator complex and its impact on RNA processing.

Main Methods:

• Co-immunoprecipitation to study BRAT1 interactions.
• Analysis of RNA processing (UsnRNAs, snoRNAs, pre-mRNAs) in BRAT1-deficient cells.
• Gene expression profiling.
• Analysis of patient-derived cells.

Main Results:

• BRAT1 interacts with INTS9/INTS11 subunits of the Integrator complex.
• BRAT1 deletion disrupts Integrator complex functions, impairing 3' end processing of UsnRNAs, snoRNAs, and replication-dependent histone pre-mRNAs.
• Altered expression of protein-coding genes was observed.
• Integrator function impairments were confirmed in patient-derived cells.

Conclusions:

• BRAT1 is essential for proper Integrator complex function.
• Defects in BRAT1 lead to aberrant RNA and protein expression due to impaired Integrator activity.
• These molecular defects contribute to the neurodegeneration observed in BRAT1-related disorders.