14-3-3 proteins inactivate DAPK2 by promoting its dimerization and protecting key regulatory phosphosites

• Published in: Communications biology Vol. 4; no. 1; p. 986
• Main Authors: Horvath, Matej, Petrvalska, Olivia, Herman, Petr, Obsilova, Veronika, Obsil, Tomas
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 19.08.2021; Nature Publishing Group; Nature Portfolio
• Subjects: 14-3-3 protein; 14-3-3 Proteins - genetics; 14-3-3 Proteins - metabolism; 631/45/275; 631/45/612/1246; 631/535/1261; 631/535/1266; 82/29; 82/58; 82/80; 82/83; Apoptosis; Autophagy; Biology; Biomedical and Life Sciences; C-Terminus; Calcium-binding protein; Calmodulin; Death-associated protein kinase; Death-Associated Protein Kinases - genetics; Death-Associated Protein Kinases - metabolism; Dephosphorylation; Dimerization; Gene Expression Regulation; Humans; Inflammation; Kinases; Leukocytes (granulocytic); Life Sciences; Phagocytosis; Phosphorylation
• ISSN: 2399-3642; 2399-3642
• DOI: 10.1038/s42003-021-02518-y

Death-associated protein kinase 2 (DAPK2) is a CaM-regulated Ser/Thr protein kinase, involved in apoptosis, autophagy, granulocyte differentiation and motility regulation, whose activity is controlled by autoinhibition, autophosphorylation, dimerization and interaction with scaffolding proteins 14-3-3. However, the structural basis of 14-3-3-mediated DAPK2 regulation remains unclear. Here, we structurally and biochemically characterize the full-length human DAPK2:14-3-3 complex by combining several biophysical techniques. The results from our X-ray crystallographic analysis revealed that Thr369 phosphorylation at the DAPK2 C terminus creates a high-affinity canonical mode III 14-3-3-binding motif, further enhanced by the diterpene glycoside Fusicoccin A. Moreover, concentration-dependent DAPK2 dimerization is disrupted by Ca 2+ /CaM binding and stabilized by 14-3-3 binding in solution, thereby protecting the DAPK2 inhibitory autophosphorylation site Ser318 against dephosphorylation and preventing Ca 2+ /CaM binding. Overall, our findings provide mechanistic insights into 14-3-3-mediated DAPK2 inhibition and highlight the potential of the DAPK2:14-3-3 complex as a target for anti‐inflammatory therapies. Horvath et al. structurally and biochemically characterize the full-length human DAPK2-14-3-3 complex to investigate the effects of binding to DAPK2 on its dimerization, activation by dephosphorylation of Ser318, and Ca 2+ /calmodulin binding. Their results provide mechanistic insights into 14- 3-3-mediated DAPK2 inhibition and highlight the potential of the DAPK2:14-3-3 complex as a target for anti-inflammatory therapies.