scholarly journals N-glycosylation of the AMPA-type glutamate receptor regulates cell surface expression and tetramer formation affecting channel function

2018 ◽  
Vol 147 (6) ◽  
pp. 730-747 ◽  
Author(s):  
Munal Babu Kandel ◽  
Saki Yamamoto ◽  
Ryosuke Midorikawa ◽  
Jyoji Morise ◽  
Yoshihiko Wakazono ◽  
...  
Keyword(s):  
Cell Surface ◽  
Glutamate Receptor ◽  
Surface Expression ◽  
Cell Surface Expression ◽  
Channel Function ◽  
Tetramer Formation

scholarly journals Characterization, cell-surface expression and ligand-binding properties of different truncated N-terminal extracellular domains of the ionotropic glutamate receptor subunit GluR1

1996 ◽  
Vol 315 (1) ◽  
pp. 217-225 ◽  
Author(s):  
R. A. Jeffrey McILHINNEY ◽  
Elek MOLNÁR
Keyword(s):  
Cell Surface ◽  
Ligand Binding ◽  
Glutamate Receptor ◽  
Cell Membranes ◽  
Surface Expression ◽  
Cell Surface Expression ◽  
Receptor Subunit ◽  
Binding Studies ◽  
Terminal Domain ◽  
Glutamate Receptor Subunit

To identify the location of the first transmembrane segment of the GluR1 glutamate receptor subunit artificial stop codons have been introduced into the N-terminal domain at amino acid positions 442, 510 and 563, namely just before and spanning the proposed first two transmembrane regions. The resultant truncated N-terminal fragments of GluR1, termed NT1, NT2 and NT3 respectively were expressed in Cos-7 cells and their cellular distribution and cell-surface expression analysed using an N-terminal antibody to GluR1. All the fragments were fully glycosylated and were found to be associated with cell membranes but none was secreted. Differential extraction of the cell membranes indicated that both NT1 and NT2 behave as peripheral membrane proteins. In contrast NT3, like the full subunit, has integral membrane protein properties. Furthermore only NT3 is expressed at the cell surface as determined by immunofluorescence and cell-surface biotinylation. Protease protection assays indicated that only NT3 had a cytoplasmic tail. Binding studies using the selective ligand [3H]α-amino-3-hydroxy-5-methyl-4-isoxazolepropionate ([3H]AMPA) demonstrated that NT3 does not bind ligand. Together these results indicate that the first transmembrane domain of the GluR1 subunit lies between residues 509 and 562, that the N-terminal domain alone cannot form a functional ligand-binding site and that this domain can be targeted to the cell surface provided that it has a transmembrane-spanning region.

scholarly journals Distinct Cell Surface Expression Patterns of N-Glycosylation Site Mutants of AMPA-Type Glutamate Receptor under the Homo-Oligomeric Expression Conditions

2020 ◽  
Vol 21 (14) ◽  
pp. 5101
Author(s):  
Jyoji Morise ◽  
Saki Yamamoto ◽  
Ryosuke Midorikawa ◽  
Kogo Takamiya ◽  
Motohiro Nonaka ◽  
...  
Keyword(s):  
Cell Surface ◽  
Glutamate Receptor ◽  
Expression Patterns ◽  
Surface Expression ◽  
Glycosylation Site ◽  
Synaptic Activity ◽  
Cell Surface Expression ◽  
Dependent Manner ◽  
Distinct Cell

The AMPA-type glutamate receptor (AMPAR) is a homotetrameric or heterotetrameric ion channel composed of various combinations of four subunits (GluA1–4), and its abundance in the synapse determines the strength of synaptic activity. The formation of oligomers in the endoplasmatic reticulum (ER) is crucial for AMPAR subunits’ ER-exit and translocation to the cell membrane. Although N-glycosylation on different AMPAR subunits has been shown to regulate the ER-exit of hetero-oligomers, its role in the ER-exit of homo-oligomers remains unclear. In this study, we investigated the role of N-glycans at GluA1N63/N363 and GluA2N370 in ER-exit under the homo-oligomeric expression conditions, whose mutants are known to show low cell surface expressions. In contrast to the N-glycosylation site mutant GluA1N63Q, the cell surface expression levels of GluA1N363Q and GluA2N370Q increased in a time-dependent manner. Unlike wild-type (WT) GluA1, GluA2WT rescued surface GluA2N370Q expression. Additionally, the expression of GluA1N63Q reduced the cell surface expression level of GluA1WT. In conclusion, our findings suggest that these N-glycans have distinct roles in the ER-exit of GluA1 and GluA2 homo-oligomers; N-glycan at GluA1N63 is a prerequisite for GluA1 ER-exit, whereas N-glycans at GluA1N363 and GluA2N370 control the ER-exit rate.

scholarly journals Actin-binding Protein α-Actinin-1 Interacts with the Metabotropic Glutamate Receptor Type 5b and Modulates the Cell Surface Expression and Function of the Receptor

2007 ◽  
Vol 282 (16) ◽  
pp. 12143-12153 ◽  
Author(s):  
Nuria Cabello ◽  
Rosaria Remelli ◽  
Laia Canela ◽  
Ana Soriguera ◽  
Josefa Mallol ◽  
...  
Keyword(s):  
Cell Surface ◽  
Glutamate Receptor ◽  
Metabotropic Glutamate Receptor ◽  
Surface Expression ◽  
Receptor Type ◽  
Actin Binding ◽  
Cell Surface Expression ◽  
Actin Binding Protein ◽  
Metabotropic Glutamate ◽  
And Function

Abstract 049: Functional Characterization of KCNQ1 Channel Subunit With an A590T Mutation

2013 ◽  
Vol 113 (suppl_1) ◽  
Author(s):  
Koshi Kinoshita ◽  
Katsuya Kimoto ◽  
Takuto Komatsu ◽  
Kohki Nishide ◽  
Toshihide Tabata ◽  
...  
Keyword(s):  
Cell Surface ◽  
Functional Characterization ◽  
Coiled Coil ◽  
Surface Expression ◽  
Cell Surface Expression ◽  
Delayed Rectifier ◽  
Wild Type ◽  
Cardiac Events ◽  
Channel Function ◽  
Similar Density

Background: KCNQ1 encodes the alpha subunit of the voltage-gated K + channel that mediates the cardiac slow delayed rectifier K + current (I Ks ). A mutation, A590T, in KCNQ1 was incidentally identified in a 40 years old female. She had a mild QTc prolongation in electrocardiogram but has never experienced any cardiac events. A590 is located in the C-terminal domain forming a coiled-coil structure, which has been suggested as a pivotal component for subunit tetramerization and channel trafficking to the cell surface. The previously reported mutations around A590 result in markedly reduced cell surface expression and loss of functional channel. We, for the first time, examined whether and how the A590T mutation affects the I Ks channel function. Methods: To assess the trafficking and channel function of KCNQ1(A590T) mutant subunit, we performed immunostaining, immunoblotting, and voltage-clamp measurements in HEK-293T cells transfected with wild-type or the A590T mutant KCNQ1 or their mixture (WT, A590T, and A590T/WT cells, respectively). Results: The density of a depolarization-activated current in the A590T cells was smaller than that in the WT cells. The threshold, half-maximal activation, and saturating voltages of the depolarization-activated current in the A590T cells were more positive than those in the WT cells. The immunoreactivity against KCNQ1 subunit on the cell surface in the A590T cells is lower than in WT cells. The A590T/WT cells had a similar density of the depolarization-activated current and a similar level of immunoreactivity against the channel subunit to the WT cells. Furthermore, the immunoblotting detected subunit oligomers in the membrane fraction of the A590T cells while their densities were lower than those of the WT cells. Conclusion: Although the A590T mutant subunit can form oligomers for itself, this subunit is not efficiently trafficked to the cell surface without the aid of the WT subunit. Thus, homozygous inheritance of the mutant KCNQ1 might be pathogenic. By contrast, the cells expressing both the mutant and wild-type KCNQ1 subunit had normal I Ks and cell surface expression, indicating that the heterozygous inheritance of the mutant KCNQ1 might not cause severe cardiac diseases.

scholarly journals A Protein Cross‐Linking Assay for Measuring Cell Surface Expression of Glutamate Receptor Subunits in the Rodent Brain After In Vivo Treatments

2012 ◽  
Vol 59 (1) ◽  
Author(s):  
Amy C. Boudreau ◽  
Mike Milovanovic ◽  
Kelly L. Conrad ◽  
Christopher Nelson ◽  
Carrie R. Ferrario ◽  
...  
Keyword(s):  
Cell Surface ◽  
Glutamate Receptor ◽  
Surface Expression ◽  
Cell Surface Expression ◽  
Cross Linking ◽  
Measuring Cell ◽  
Rodent Brain ◽  
Protein Cross Linking

scholarly journals Cell surface expression of the metabotropic glutamate receptor type 1α is regulated by the C-terminal tail

FEBS Letters ◽  
1999 ◽  
Vol 448 (1) ◽  
pp. 91-94 ◽  
Author(s):  
F. Ciruela ◽  
M.M. Soloviev ◽  
R.A.J. McIlhinney
Keyword(s):  
Cell Surface ◽  
Glutamate Receptor ◽  
Metabotropic Glutamate Receptor ◽  
Surface Expression ◽  
Receptor Type ◽  
Cell Surface Expression ◽  
Metabotropic Glutamate

scholarly journals Annexin A5 increases the cell surface expression and the chloride channel function of the ΔF508-cystic fibrosis transmembrane regulator

2008 ◽  
Vol 1782 (10) ◽  
pp. 605-614 ◽  
Author(s):  
Marie-Anne Le Drévo ◽  
Nathalie Benz ◽  
Mathieu Kerbiriou ◽  
Marie-Agnès Giroux-Metges ◽  
Jean-Pierre Pennec ◽  
...  
Keyword(s):  
Cystic Fibrosis ◽  
Cell Surface ◽  
Chloride Channel ◽  
Surface Expression ◽  
Cystic Fibrosis Transmembrane Regulator ◽  
Cell Surface Expression ◽  
Annexin A5 ◽  
Channel Function ◽  
Cystic Fibrosis Transmembrane

Homer-Dependent Cell Surface Expression of Metabotropic Glutamate Receptor Type 5 in Neurons

2002 ◽  
Vol 20 (2) ◽  
pp. 323-329 ◽  
Author(s):  
Fabrice Ango ◽  
David Robbe ◽  
Jian Cheng Tu ◽  
Bo Xiao ◽  
Paul F. Worley ◽  
...  
Keyword(s):  
Cell Surface ◽  
Glutamate Receptor ◽  
Metabotropic Glutamate Receptor ◽  
Surface Expression ◽  
Receptor Type ◽  
Cell Surface Expression ◽  
Metabotropic Glutamate ◽  
Dependent Cell
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