2024-03-29T02:13:55Zhttp://digital.csic.es/dspace-oai/requestoai:digital.csic.es:10261/326162022-01-04T11:25:48Zcom_10261_133com_10261_1col_10261_386
Characterization of alternatively spliced isoforms of AMPA receptor subunits encoding truncated receptors
Gomes, André R.
Ferreira, Joana S.
Paternain, Ana V.
Lerma Gómez, Juan
Duarte, Carlos B.
Carvalho, Ana Luisa
Flip/flop
Dominant negative
Excitotoxicity
Neuroprotection
Synaptic targeting
12 páginas, 5 figuras.
Glutamate receptors of the α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA)-type play an important role in synaptic plasticity and contribute to cell death under excitotoxic conditions. AMPA receptors form heterotetramers of four homologous subunits (GluR1–4), which exist in two functionally different isoforms, flip and flop, generated by alternative splicing. We identified transcripts for alternatively spliced isoforms of AMPA receptor subunits which lack both the flip and the flop exons, in hippocampal and retinal cultures. These transcripts originate AMPA receptor subunits lacking the flip/flop cassette, the fourth transmembrane domain and the intracellular C-terminus. Truncated GluR1 associates with full-length GluR1 and exerts a dominant negative effect, giving rise to non-functional receptors. Moreover, truncated GluR1 reaches the cell surface, but is not efficiently targeted to the synapse. Hippocampal neuronal transfection with truncated GluR1 resulted in a significant reduction in apoptotic neuronal death triggered by toxic concentrations of glutamate. Furthermore, mRNA coding for the truncated subunits is consistently detected in some regions of the brain in epileptic rats and in hippocampal neurons submitted to toxic concentrations of glutamate. The existence of truncated AMPA receptor subunits may constitute an intrinsic neuroprotective mechanism.
This work was supported by Fundação para a Ciência e a
Tecnologia, Portugal (SFRH/BD/1286/2000, POCTI/BCI/39127/
2001 and POCI/SAU-NEU/58955/2004) and the BFU2006-07138
grant to JL.
Peer reviewed
2011-02-21T11:02:57Z
2011-02-21T11:02:57Z
2008-02
artículo
http://purl.org/coar/resource_type/c_6501
Molecular and Cellular Neurosciences 37(2): 323-334 (2008)
1044-7431
http://hdl.handle.net/10261/32616
10.1016/j.mcn.2007.10.008
en
http://dx.doi.org/10.1016/j.mcn.2007.10.008
none
Elsevier