Download MendeleyStructural basis for the Ca 2+ /CaM-mediated regulation of CASK-CaMK.
Li, W., Wang, Y., Feng, W.(2025) Int J Biol Macromol 332: 148495-148495
- PubMed: 41151710
- DOI: https://doi.org/10.1016/j.ijbiomac.2025.148495
- Primary Citation of Related Structures:
8Y68, 9KYS, 9M5Y, 9M6G - PubMed Abstract:
As a member of the Ca 2+ /CaM-dependent protein kinase family, CASK contains an N-terminal CaMK domain that is regulated by Ca 2+ -bound CaM, while the underlying mechanism remains to be elucidated. Here, we determine the crystal structures of CASK-CaMK in different states: apo CASK-CaMK, CASK-CaMK in complex with CaM (the CaM-CASK complex) and CASK-CaMK in complex with CaM and Mint1 (the CaM-CASK-Mint1 complex). CASK-CaMK exhibits an inhibitory conformation with the αR2 helix of the autoregulatory domain (ARD) inserting into its nucleotide-binding pocket. Contrary to conventional CaM-mediated binding paradigms, in the CaM-CASK complex, only the C-terminal lobe of CaM (C-CaM) engages with the ARD of CASK-CaMK. This C-CaM binding induces the formation of an extended ARD α-helix that reshapes the nucleotide-binding pocket of CASK-CaMK to enhance its nucleotide-binding capacity. Correspondingly, in the CaM-CASK-Mint1 complex, similar C-CaM binding to CASK-CaMK leads to a slight opening of the CASK-Mint1 complex, and only the Mint1-CID (CASK-interaction domain) core is resolved association with CASK-CaMK. Taken together, CaM likely regulates CASK-CaMK through a C-CaM-dependent mechanism to tune its nucleotide-binding and target-recognition capacities.
- State Key Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, 15 Datun Road, Beijing, 100101, China. Electronic address: liwei@ibp.ac.cn.
Organizational Affiliation:
