BACKGROUND: Emerging evidence implicates that tau SUMOylation disrupts tau homeostasis. Death-associated protein kinase 1 (DAPK1) has been shown to affect tau phosphorylation and accumulation. The sentrin-specific protease 1 (SENP1) is important for protein SUMOylation, and is a potential substrate of DAPK1. However, whether DAPK1 regulates tau SUMOylation and proteostasis through modulating SENP1 remains elusive. METHODS: We identified the phosphorylation of SENP1 by DAPK1 using in vitro kinase...