CARM1 automethylation is controlled at the level of alternative splicing.

Co-activator-associated arginine methyltransferase 1 (CARM1) is subjected to multiple post-translational modifications. Our previous finding that automethylation of CARM1 is essential for regulation of transcription and pre-mRNA splicing prompted us to investigate how automethylation is regulated. Here, we report that automethylation is regulated by alternative splicing of CARM1 mRNA to remove exon 15, containing the automethylation site.