Dual specificity kinase acting on both serine/threonine and tyrosine-containing substrates. Phosphorylates serine- and arginine- rich (SR) proteins of the spliceosomal complex. May be a constituent of a network of regulatory mechanisms that enable SR proteins to control RNA splicing and can cause redistribution of SR proteins from speckles to a diffuse nucleoplasmic distribution. Phosphorylates SRSF1 and SRSF3. Regulates the alternative splicing of tissue factor (F3) pre- mRNA in endothelial cells. {ECO:0000269|PubMed:19168442, ECO:0000269|PubMed:9637771}. This is the function of ENSG00000179335 (CLK3, CDC like kinase 3).