Characterization of molecular mechanisms of CaMKKα/1 oligomerization

Calcium/calmodulin-dependent protein kinase kinase (CaMKK) is an activating kinase for calcium/calmodulin-dependent protein kinase type 1 (CaMKI), calcium/calmodulin-dependent protein kinase type IV (CaMKIV), RAC-alpha serine/threonine-protein kinase (PKB), and AMP-activated protein kinase (AMPK) that has been reported to form an active oligomer in cells. Glutathione S-transferase (GST) pulldown assay from the extracts of COS-7 cells expressing GST- and His6-CaMKKα/1 mutants showed that the C-terminal region containing the autoinhibitory and calmodulin (CaM)-binding sequence (residues 438–463) is required for CaMKKα/1 homo-oligomerization. This was confirmed by the fact that the GST-CaMKKα/1 C-terminal domain (residues 435–505) directly interacted with EGFP-CaMKKα/1 residues 435–505 as well as with wild-type CaMKKα/1. Notably, once oligomerized in cells, CaMKKα/1 is neither exchangeable between the oligomeric complexes nor dissociated by Ca2+/CaM binding. These results support stable oligomerization of CaMKK in the cells by intermolecular self-association of its C-terminal region containing a regulatory domain.

This is the peer reviewed version of the following article: [Uenoyama, S., Nitta, H., Ohtsuka, S., Magari, M., Suizu, F. and Tokumitsu, H. (2025), Characterization of molecular mechanisms of CaMKKα/1 oligomerization. FEBS Lett, 599: 1914-1924. https://doi.org/10.1002/1873-3468.70078], which has been published in final form at [https://doi.org/10.1002/1873-3468.70078]. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Use of Self-Archived Versions. This article may not be enhanced, enriched or otherwise transformed into a derivative work, without express permission from Wiley or by statutory rights under applicable legislation. Copyright notices must not be removed, obscured or modified. The article must be linked to Wiley’s version of record on Wiley Online Library and any embedding, framing or otherwise making available the article or pages thereof by third parties from platforms, services and websites other than Wiley Online Library must be prohibited.

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