Pro-death NMDA receptor signaling is promoted by the GluN2B C-terminus independently of DAPK1
- Edinburgh Medical School, University of Edinburgh, United Kingdom
- Trinity College Dublin, Ireland
- University of Edinburgh, United Kingdom
- The Roslin Institute, United Kingdom
- Wellcome Trust Sanger Institute, United Kingdom
Abstract
Aberrant NMDA receptor (NMDAR) activity contributes to several neurological disorders, but direct antagonism is poorly tolerated therapeutically. The GluN2B cytoplasmic C-terminal domain (CTD) represents an alternative therapeutic target since it potentiates excitotoxic signaling. The key GluN2B CTD-centred event in excitotoxicity is proposed to involve its phosphorylation at Ser-1303 by DAPK1, that is blocked by a neuroprotective cell-permeable peptide mimetic of the region. Contrary to this model, we find that excitotoxicity can proceed without increased Ser-1303 phosphorylation, and is unaffected by DAPK1 deficiency in vitro or following ischemia in vivo. Pharmacological analysis of the aforementioned neuroprotective peptide revealed that it acts in a sequence-independent manner as an open-channel NMDAR antagonist at or near the Mg2+ site, due to its high net positive charge. Thus, GluN2B-driven excitotoxic signaling can proceed independently of DAPK1 or altered Ser-1303 phosphorylation.
Article and author information
Author details
Giles E Hardingham
Funding
Wellcome (WT088156)
- Giles E Hardingham
Medical Research Council (MRC_G0902044)
- Jamie McQueen
- Sean McKay
- Paul E Baxter
- Giles E Hardingham
The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.
Ethics
Animal experimentation: All experiments using live animals were conducted under the authority of UK Home Office project and personal licences and adhered to regulations specified in the Animals (Scientific Procedures) Act (1986) and Directive 2010/63/EU and were approved by both The Roslin Institute's and the University of Edinburgh's Animal Welfare and Ethics Committees. Experimental design, analysis and reporting followed the ARRIVE guidelines (https://www.nc3rs.org.uk/arrive-guidelines) where possible. Animal experimentation: Animals used in this study were treated in accordance with UK Animal Scientific Procedures Act (1986) . The relevant Home Office project licences are P1351480E and 60/4407, and the use of genetically modified organisms approved by local committee reference SBMS 13_007.
Copyright
© 2017, McQueen et al.
This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.
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