Calcium/Calmodulin Dependent Protein Kinase II Bound to NMDA Receptor 2B Subunit Exhibits Increased ATP Affinity and Attenuated Dephosphorylation

Cheriyan, John and Kumar, Parimal and Mayadevi, Madhavan and Surolia, Avadhesha and Omkumar, Ramakrishnapillai V (2011) Calcium/Calmodulin Dependent Protein Kinase II Bound to NMDA Receptor 2B Subunit Exhibits Increased ATP Affinity and Attenuated Dephosphorylation. In: PLos One, 6 (3).

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Abstract

Calcium/calmodulin dependent protein kinase II (CaMKII) is implicated to play a key role in learning and memory. NR2B subunit of N-methyl-D-aspartate receptor (NMDAR) is a high affinity binding partner of CaMKII at the postsynaptic membrane. NR2B binds to the T-site of CaMKII and modulates its catalysis. By direct measurement using isothermal titration calorimetry (ITC), we show that NR2B binding causes about 11 fold increase in the affinity of CaMKII for ATP gamma S, an analogue of ATP. ITC data is also consistent with an ordered binding mechanism for CaMKII with ATP binding the catalytic site first followed by peptide substrate. We also show that dephosphorylation of phospho-Thr(286)-alpha-CaMKII is attenuated when NR2B is bound to CaMKII. This favors the persistence of Thr(286) autophosphorylated state of CaMKII in a CaMKII/phosphatase conjugate system in vitro. Overall our data indicate that the NR2B- bound state of CaMKII attains unique biochemical properties which could help in the efficient functioning of the proposed molecular switch supporting synaptic memory.

Item Type:	Journal Article
Publication:	PLos One
Publisher:	Public Library of Science
Additional Information:	Copyright of this article belongs to Public Library of Science.
Department/Centre:	Division of Biological Sciences > Molecular Biophysics Unit
Date Deposited:	20 Apr 2011 06:37
Last Modified:	20 Apr 2011 06:37
URI:	http://eprints.iisc.ac.in/id/eprint/36726

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