The Interaction between the Drosophila EAG Potassium Channel and the Protein Kinase CaMKII Involves an Extensive Interface at the Active Site of the Kinase

JOURNAL OF MOLECULAR BIOLOGY

卷:430

Article

Castro-Rodrigues, Artur F.^1,2  Zhao, Yaxian³  Fonseca, Fatima^1,2  Gabant, Guillaume⁴  Cadene, Martine⁴  Robertson, Gail A.³  Morais-Cabral, Joao H.^1,2 

[1] Univ Porto, IBMC, Porto, Portugal

[2] Univ Porto, i3S, Porto, Portugal

[3] Univ Wisconsin, Sch Med & Publ Hlth, Dept Neurosci, Madison, WI USA

[4] CNRS, UPR430, Ctr Biophys Mol, Orleans, France

关键词: channel-kinase interaction;    NMDA receptor;    kinase-substrate structure;    isothermal calorimetry;   

DOI  :  10.1016/j.jmb.2018.10.015

来源: Elsevier

【 摘 要 】

The Drosophila EAG (dEAG) potassium channel is the founding member of the superfamily of KNCH channels, which are involved in cardiac repolarization, neuronal excitability and cellular proliferation. In flies, dEAG is involved in regulation of neuron firing and assembles with CaMKII to form a complex implicated in memory formation. We have characterized the interaction between the kinase domain of CaMKII and a 53-residue fragment of the dEAG channel that includes a canonical CaMKII recognition sequence. Crystal structures together with biochemical/biophysical analysis show a substrate kinase complex with an unusually tight and extensive interface that appears to be strengthened by phosphorylation of the channel fragment. Electrophysiological recordings show that catalytically active CaMKII is required to observe active dEAG channels. A previously identified phosphorylation site in the recognition sequence is not the substrate for this crucial kinase activity, but rather contributes importantly to the tight interaction of the kinase with the channel. The available data suggest that the dEAG channel is a docking platform for the kinase and that phosphorylation of the channel's kinase recognition sequence modulates the strength of the interaction between the channel and the kinase. (C) 2018 Elsevier Ltd. All rights reserved.

【 授权许可】

Free