Tyrosine kinase 2 interacts with the proapoptotic protein Siva-1 and augments its apoptotic functions

► Tyk2 interacts with the proapoptotic protein Siva-1 via its N-terminus region. ► Tyk2 phosphorylates Siva-1, which has little effect on Siva-1-induced apoptosis. ► Tyk2 augments the apoptotic function of Siva-1 through the Tyk2-Siva-1 interaction.