Oxidation of CaMKIIα cysteines inhibits autonomous activation induced by phosphorylation.

Autor: Rocco-Machado N; Laboratory of Biochemistry, National Heart, Lung and Blood Institute, Maryland, USA. Electronic address: nathalia.roccomachado@nih.gov., Deng M; Laboratory of Biochemistry, National Heart, Lung and Blood Institute, Maryland, USA., He Y; Fermentation Facility, National Heart, Lung, and Blood Institute, National Institutes of Health, Maryland, USA., Levine RL; Laboratory of Biochemistry, National Heart, Lung and Blood Institute, Maryland, USA. Electronic address: rlevine@nih.gov.
Jazyk: angličtina
Zdroj: Archives of biochemistry and biophysics [Arch Biochem Biophys] 2024 Dec 12; Vol. 764, pp. 110268. Date of Electronic Publication: 2024 Dec 12.
DOI: 10.1016/j.abb.2024.110268
Abstrakt: Ca 2+ /calmodulin-dependent protein kinase II α (CaMKIIα) "autonomous" activation induced by Thr286 phosphorylation has a crucial role in synaptic plasticity. Previous studies showed that in Alzheimer's disease brain, CaMKIIα autophosphorylation at Thr286 is reduced while the level of cysteine-oxidized CAMKIIα is elevated. We performed tryptic mapping of the oxidized CaMKIIα and discovered the formation of a disulfide between the N-terminal Cys6 and the regulatory domain Cys280. The apparent pK a values of Cys6 and Cys280 are 7.1 and 7.7, respectively, lower than the 8.5 for free Cys. The low apparent pK a of Cys6 facilitates the oxidation of its thiol to the sulfenic acid at physiological pH. The thiolate of Cys280 can then attack the sulfenic acid to form a disulfide. Using an antibody against phosphorylated Thr286, we showed that disulfide formation prevents Thr286 phosphorylation. CaMKIIα autonomous activation induced by disulfide formation is much lower than the autonomous activation induced by phosphorylation. The decreased autonomous activation may contribute to the synaptic impairment of Alzheimer's disease. We also generated a CaMKIIα mutant in which Cys6 was mutated to Ser6. This mutation prevented disulfide formation and restored autonomous activation induced by phosphorylation. Our findings provide insight into the mechanistic details of CaMKIIα autonomous activation induced by disulfide formation that may contribute to the impairment of long-term potentiation in Alzheimer's disease.
Competing Interests: Conflict of interest The authors declare that they have no conflicts of interest with the contents of this article.
(Copyright © 2024 Elsevier Inc. All rights reserved.)
Databáze: MEDLINE
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