Enables kinase activator activity. Acts upstream of or within several processes, including circulatory system development; positive regulation of MAPK cascade; and transforming growth factor beta receptor signaling pathway. Predicted to be located in nuclear speck. Predicted to be part of protein-containing complex. Predicted to be active in cytosol and nucleus. Is expressed in genitourinary system. Orthologous to human TAB1 (TGF-beta activated kinase 1 (MAP3K7) binding protein 1). [provided by Alliance of Genome Resources, Apr 2022]