Contribution of the Dido gene to RNA splicing in Mus musculus

The study evaluated the contribution of the Death inducer obliterator (Dido, DIDO1) gene to RNA splicing. The Dido gene in mammals produces three isoforms, termed Dido1, Dido2, and Dido3. All three isoforms contain a PHD domain that binds H3K4Me3. Dido2 and Dido3 share a central region that comprises TFS2M and SPOC domains, predicted to bind RNA polymerase II. The Dido3 isoform contains a long carboxy-terminal region of unknown function. The focus of this study was on the largest (Dido3) variant, which comprises a complete domain structure. Protein interaction studies reveal a modular makeup for Dido3, in which a variety of proteins bind to the different domains. Apart from the previously described interactions, the Dido3-specific protein region interacts with SFPQ. To evaluate the contribution of individual protein domains to gene function, deletion mutants corresponding to the amino-terminal (delta NT / TM1 ) and carboxy-terminal domain (delta E16 / TM3.1) were generated and subjected to mRNA sequencing. Mouse embryonic fibroblasts were prepared from E13.5 embryos, immortalized by pBabe-puro transduction of HPV E6 and E7 genes, and cultured for 10 to 15 passages. Mouse embryonic fibroblasts derived from wild-type littermates were used as controls, and biological triplicates were prepared for all samples. Subsequent RNA sequencing revealed extensive exon skipping in the mutant lacking the SFPQ binding region but partial conservation of function in the mutant lacking the H3K4Me3 recognition domain.