Papadakis, M., Hawkins, L.M. and Stephenson, F.A. (2004) Appropriate NR1-NR1 disulfide-linked homodimer formation is requisite for efficient expression of functional, cell surface N-methyl-D-aspartate NR1/NR2 receptors. Journal of Biological Chemistry, 279 (15). pp. 14703-14712. 10.1074/jbc.M313446200 .
Full text not available from this repository.
Official URL: http://www.jbc.org/content/279/15/14703.full.pdf+html
A c-Myc epitope-tagged N-methyl-D-aspartate receptor NR1-2a subunit was generated, NR1-2a(c-Myc), where the tag was inserted after amino acid 81. NR1-2a(c-Myc) /NR2A receptors when expressed in mammalian cells are not trafficked to the cell surface nor do they yield cell cytotoxicity post-transfection. NR1-2a(c-Myc) was, however, shown to assemble with NR2A subunits by immunoprecipitation and [(3)H]MK801 radioligand binding assays. Immunoblots of cells co-transfected with wild-type NR1-2a/NR2A subunits yielded two NR1-2a immunoreactive species with molecular masses of 115 and 226 kDa. Two-dimensional electrophoresis under non-reducing and reducing conditions revealed that the 226-kDa band contained disulfide-linked NR1-2a subunits. Only the 115-kDa NR1-2a species was detected for NR1-2a(c-Myc)/NR2A. The c-Myc epitope is inserted adjacent to cysteine 79 of the NR1-2a subunit; therefore, it is possible that the tag may prevent the formation of NR1 disulfide bridges. A series of cysteine --> alanine NR1-2a mutants was generated, and the NR1-2a mutants were co-expressed with NR2A or NR2B subunits in mammalian cells and characterized with respect to cell surface expression, cell cytotoxicity post-transfection, co-association by immunoprecipitation, and immunoblotting following SDS-PAGE under both reducing and non-reducing conditions. When co-expressed with NR2A in mammalian cells, NR1-2a(C79A)/NR2A displayed similar properties to NR1-2a(c-Myc)/NR2A in that the 226-kDa NR1 immunoreactive species was not detectable, and trafficking to the cell surface was impaired compared with wild-type NR1/NR2 receptors. These results provide the first biochemical evidence for the formation of NR1-NR1 intersubunit disulfide-linked homodimers involving cysteine 79. They suggest that disulfide bridging and structural integrity within the NR1 N-terminal domain is requisite for cell surface N-methyl-D-aspartate receptor expression.
|Departments, units and centres:||Department of Pharmaceutical and Biological Chemistry > Department of Pharmaceutical and Biological Chemistry|
|Journal or Publication Title:||Journal of Biological Chemistry|
|Deposited By:||Library Staff|
|Deposited On:||24 Nov 2011 10:17|
|Last Modified:||24 Nov 2011 10:17|
Item downloaded times since 24 Nov 2011 10:17.
Repository Staff Only: Item control page
School of Pharmacy Staff Only: Edit a copy to replace this item