MATR3 pathogenic variants differentially impair its cryptic splicing repression function

MATR3 is a splicing regulator implicated in neurodegenerative and neurodevelopmental diseases, but its role in cryptic splicing repression within functional genes is unclear. Here, we show that MATR3 loss leads to cryptic exon inclusion in many functional genes. We also show that two disease-associated variants differentially affect MATR3 properties, solubility, and RNA binding, thereby impacting its cryptic splicing repression function. Matrin-3 (MATR3) is an RNA-binding protein implicated in neurodegenerative and neurodevelopmental diseases. However, little is known regarding the role of MATR3 in cryptic splicing within the context of functional genes and how disease-associated variants impact this function. We show that loss of MATR3 leads to cryptic exon inclusion in many transcripts. We reveal that ALS-linked S85C pathogenic variant reduces MATR3 solubility but does not impair RNA binding. In parallel, we report a novel neurodevelopmental disease-associated M548T variant, located in the RRM2 domain, which reduces protein solubility and impairs RNA binding and cryptic splicing repression functions of MATR3. Altogether, our research identifies cryptic events within functional genes and demonstrates how disease-associated variants impact MATR3 cryptic splicing repression function.
Source: FEBS Letters - Category: Biochemistry Authors: Tags: Research Article Source Type: research