CaMKK2 kinase domain interacts with the autoinhibitory region through the N-terminal lobe including the RP insert
| Autor: | Salome Kylarova, Veronika Obsilova, Tomas Obsil, Katarina Psenakova, Petr Herman |
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| Rok vydání: | 2018 |
| Předmět: |
Models
Molecular 0301 basic medicine Calmodulin Protein Conformation Biophysics Calcium-Calmodulin-Dependent Protein Kinase Kinase Biochemistry Protein–protein interaction 03 medical and health sciences Protein Domains Humans Phosphorylation Protein kinase A Molecular Biology CAMK CAMKK2 030102 biochemistry & molecular biology biology Activator (genetics) Chemistry Kinase Cell biology 030104 developmental biology Protein kinase domain biology.protein Calcium Protein Binding |
| Zdroj: | Biochimica et Biophysica Acta (BBA) - General Subjects. 1862:2304-2313 |
| ISSN: | 0304-4165 |
| Popis: | Background Calcium/calmodulin-dependent protein kinase kinase 2 (CaMKK2), a member of the Ca2+/calmodulin-dependent kinase (CaMK) family, functions as an upstream activator of CaMKI, CaMKIV and AMP-activated protein kinase. Thus, CaMKK2 is involved in the regulation of several key physiological and pathophysiological processes. Previous studies have suggested that Ca2+/CaM binding may cause unique conformational changes in the CaMKKs compared with other CaMKs. However, the underlying mechanistic details remain unclear. Methods In this study, hydrogen-deuterium exchange coupled to mass spectrometry, time-resolved fluorescence spectroscopy, small-angle x-ray scattering and chemical cross-linking were used to characterize Ca2+/CaM binding-induced structural changes in CaMKK2. Results Our data suggest that: (i) the CaMKK2 kinase domain interacts with the autoinhibitory region (AID) through the N-terminal lobe of the kinase domain including the RP insert, a segment important for targeting downstream substrate kinases; (ii) Ca2+/CaM binding affects the structure of several regions surrounding the ATP-binding pocket, including the activation segment; (iii) although the CaMKK2:Ca2+/CaM complex shows high conformational flexibility, most of its molecules are rather compact; and (iv) AID-bound Ca2+/CaM transiently interacts with the CaMKK2 kinase domain. Conclusions Interactions between the CaMKK2 kinase domain and the AID differ from those of other CaMKs. In the absence of Ca2+/CaM binding the autoinhibitory region inhibits CaMKK2 by both blocking access to the RP insert and by affecting the structure of the ATP-binding pocket. General significance Our results corroborate the hypothesis that Ca2+/CaM binding causes unique conformational changes in the CaMKKs relative to other CaMKs. |
| Databáze: | OpenAIRE |
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