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From Proteopedia
Structure of 14-3-3 gamma in complex with CaMKK2 14-3-3 binding motif Ser511
Structural highlights
Function[1433G_HUMAN] Adapter protein implicated in the regulation of a large spectrum of both general and specialized signaling pathways. Binds to a large number of partners, usually by recognition of a phosphoserine or phosphothreonine motif. Binding generally results in the modulation of the activity of the binding partner.[1] [KKCC2_HUMAN] Calcium/calmodulin-dependent protein kinase belonging to a proposed calcium-triggered signaling cascade involved in a number of cellular processes. Isoform 1, isoform 2 and isoform 3 phosphorylate CAMK1 and CAMK4. Isoform 3 phosphorylates CAMK1D. Isoform 4, isoform 5 and isoform 6 lacking part of the calmodulin-binding domain are inactive. Efficiently phosphorylates 5'-AMP-activated protein kinase (AMPK) trimer, including that consisting of PRKAA1, PRKAB1 and PRKAG1. This phosphorylation is stimulated in response to Ca(2+) signals (By similarity). Seems to be involved in hippocampal activation of CREB1 (By similarity). May play a role in neurite growth. Isoform 3 may promote neurite elongation, while isoform 1 may promoter neurite branching.[2] [3] [4] [5] Publication Abstract from PubMedBACKGROUND: Calcium/calmodulin-dependent protein kinase kinase 2 (CaMKK2) is a member of the Ca(2+)/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 14-3-3gamma 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 14-3-3gamma dimer. Furthermore, 14-3-3gamma 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: 14-3-3gamma protein directly interacts with the kinase domain of CaMKK2 and the region containing the inhibitory phosphorylation site Thr(145) 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. 14-3-3 protein directly interacts with the kinase domain of calcium/calmodulin-dependent protein kinase kinase (CaMKK2).,Psenakova K, Petrvalska O, Kylarova S, Lentini Santo D, Kalabova D, Herman P, Obsilova V, Obsil T Biochim Biophys Acta. 2018 Apr 10. pii: S0304-4165(18)30099-0. doi:, 10.1016/j.bbagen.2018.04.006. PMID:29649512[6] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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