Abstract |
EFhd2 is a calcium binding protein, which is highly expressed in the central nervous system and associated with pathological forms of tau proteins in tauopathies. Previous phosphoproteomics studies and bioinformatics analysis suggest that EFhd2 may be phosphorylated. Here, we determine whether Cdk5, a hyperactivated kinase in tauopathies, phosphorylates EFhd2 and influence its known molecular activities. The results indicated that EFhd2 is phosphorylated by brain extract of the transgenic mouse CK-p25, which overexpresses the Cdk5 constitutive activator p25. Consistently, in vitro kinase assays demonstrated that Cdk5, but not GSK3β, directly phosphorylates EFhd2. Biomass, tandem mass spectrometry, and mutagenesis analyses indicated that Cdk5 monophosphorylates EFhd2 at S74, but not the adjacent S76. Furthermore, Cdk5-mediated phosphorylation of EFhd2 affected its calcium binding activity. Finally, a phospho-specific antibody was generated against EFhd2 phosphorylated at S74 and was used to detect this phosphorylation event in postmortem brain tissue from Alzheimer's disease and normal-aging control cases. Results demonstrated that EFhd2 is phosphorylated in vivo at S74. These results imply that EFhd2's physiological and/or pathological function could be regulated by its phosphorylation state.
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Authors | Edwin Vázquez-Rosa, Eva N Rodríguez-Cruz, Sybelle Serrano, Lucelenie Rodríguez-Laureano, Irving E Vega |
Journal | Protein science : a publication of the Protein Society
(Protein Sci)
Vol. 23
Issue 9
Pg. 1197-207
(Sep 2014)
ISSN: 1469-896X [Electronic] United States |
PMID | 24917152
(Publication Type: Journal Article, Research Support, N.I.H., Extramural)
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Copyright | © 2014 The Protein Society. |
Chemical References |
- Calcium-Binding Proteins
- EFHD2 protein, human
- Cyclin-Dependent Kinase 5
- CDK5 protein, human
- Cdk5 protein, mouse
- Calcium
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Topics |
- Animals
- Binding Sites
- Calcium
(chemistry, metabolism)
- Calcium-Binding Proteins
(chemistry, genetics, metabolism)
- Cyclin-Dependent Kinase 5
(metabolism)
- Humans
- Mice
- Mice, Transgenic
- Mutation
- Phosphorylation
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