Figure 8: A model of RBM25-mediated HAB1 alternative splicing by which HAB1 splice variants control ABA signalling.
From: ABA signalling is fine-tuned by antagonistic HAB1 variants
We suggest that RBM25 can bind to the last intron of HAB1 pre-mRNA and regulate the alternative splicing of HAB1 producing two splice variants HAB1.1 and HAB1.2. HAB1.1 contains four exons and encodes a protein, which interacts with the SnRK2.6/OST1 and inhibits its kinase activity switching the ABA signalling off; HAB1.2 contains four exons and the last intron and encodes a truncate protein lacking 105 amino acids at the C-terminal end. HAB1.2 still interacts with the SnRK2/OST1 but cannot inhibit its kinase activity, thereby keeping ABA signalling on.
