Background: Calcium/calmodulin-dependent protein kinase kinase 2 (CaMKK2) is a member of the Ca/calmodulin-dependent kinase (CaMK) family involved in adiposity regulation, glucose homeostasis and cancer. This upstream activator of CaMKI, CaMKIV and AMP-activated protein kinase is inhibited by phosphorylation, which also triggers an association with the scaffolding protein 14-3-3. However, the role of 14-3-3 in the regulation of CaMKK2 remains unknown.
Methods: The interaction between phosphorylated CaMKK2 and the 14-3-3γ protein, as well as the architecture of their complex, were studied using enzyme activity measurements, small-angle x-ray scattering (SAXS), time-resolved fluorescence spectroscopy and protein crystallography.
Results: Our data suggest that the 14-3-3 protein binding does not inhibit the catalytic activity of phosphorylated CaMKK2 but rather slows down its dephosphorylation. Structural analysis indicated that the complex is flexible and that CaMKK2 is located outside the phosphopeptide-binding central channel of the 14-3-3γ dimer. Furthermore, 14-3-3γ appears to interact with and affect the structure of several regions of CaMKK2 outside the 14-3-3 binding motifs. In addition, the structural basis of interactions between 14-3-3 and the 14-3-3 binding motifs of CaMKK2 were elucidated by determining the crystal structures of phosphopeptides containing these motifs bound to 14-3-3.
Conclusions: 14-3-3γ protein directly interacts with the kinase domain of CaMKK2 and the region containing the inhibitory phosphorylation site Thr within the N-terminal extension.
General Significance: Our results suggested that CaMKK isoforms differ in their 14-3-3-mediated regulations and that the interaction between 14-3-3 protein and the N-terminal 14-3-3-binding motif of CaMKK2 might be stabilized by small-molecule compounds.
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http://dx.doi.org/10.1016/j.bbagen.2018.04.006 | DOI Listing |
Trends Microbiol
December 2024
Ministry of Agriculture Key Laboratory of Molecular Biology of Crop Pathogens and Insect Pests, Institute of Biotechnology, Zhejiang University, Hangzhou 310058, China; Key Laboratory of Biology of Crop Pathogens and Insects of Zhejiang Province, Institute of Biotechnology, Zhejiang University, Hangzhou 310058, China; National Key Laboratory for Rice Biology and Breeding, Institute of Biotechnology, Zhejiang University, Hangzhou 310058, China. Electronic address:
Protein PARylation is a reversible post-translational modification; however, its role in fungal virulence has remained elusive. Recently, Gao et al. demonstrated that PARylation of two 14-3-3 regulatory proteins by poly(ADP-ribose) polymerase is essential for the virulence of rice blast fungus, highlighting the critical regulatory function of PARylation in fungal pathogenicity.
View Article and Find Full Text PDFFront Mol Biosci
December 2024
Amity Institute of Biotechnology, Amity University Uttar Pradesh, Lucknow, India.
Int J Mol Sci
November 2024
Almazov National Medical Research Centre, 197341 Saint Petersburg, Russia.
The adenomas in Cushing's disease frequently exhibit mutations in exon 14, within a binding motif for the regulatory protein 14-3-3 located between the catalytic domain (DUB), responsible for ubiquitin hydrolysis, and the WW-like domain that mediates autoinhibition, resulting in constantly active USP8. The exact molecular mechanism of deubiquitinase activity disruption in Cushing's disease remains unclear. To address this, Sanger sequencing of was performed to identify mutations in corticotropinomas.
View Article and Find Full Text PDFJ Neurol
December 2024
The UK National CJD Research and Surveillance Unit, Centre for Clinical Brain Sciences, Chancellor's Building, University of Edinburgh, Edinburgh, EH16 4TG, UK.
Background: Sporadic Creutzfeldt-Jakob disease (sCJD) is a rapidly progressive and fatal prion disease with significant public health implications. Survival is heterogenous, posing challenges for prognostication and care planning. We developed a survival model using diagnostic data from comprehensive UK sCJD surveillance.
View Article and Find Full Text PDFActa Neurol Belg
December 2024
Department of Cognitive Disorder, Beijing Tiantan Hospital, Capital Medical University, Fengtai District, South 4th Ring Road West 119, Beijing, 100070, China.
Objectives: Creutzfeldt-Jakob disease (CJD) is a transmissible neurodegenerative disorder with a fatal outcome. The present study investigated the difference on demographic, clinical and laboratory data between the patients with sporadic CJD (sCJD) and genetic CJD (gCJD).
Methods: Thirty-eight patients with CJD were enrolled in this study, including 28 patients with sCJD and 10 patients with gCJD.
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