Alternative splicing-mediated targeting of the Arabidopsis GLUTAMATE RECEPTOR3.5 to mitochondria affects organelle morphology.
Plant Physiol
; 167(1): 216-27, 2015 Jan.
Article
en En
| MEDLINE
| ID: mdl-25367859
ABSTRACT
Since the discovery of 20 genes encoding for putative ionotropic glutamate receptors in the Arabidopsis (Arabidopsis thaliana) genome, there has been considerable interest in uncovering their physiological functions. For many of these receptors, neither their channel formation and/or physiological roles nor their localization within the plant cells is known. Here, we provide, to our knowledge, new information about in vivo protein localization and give insight into the biological roles of the so-far uncharacterized Arabidopsis GLUTAMATE RECEPTOR3.5 (AtGLR3.5), a member of subfamily 3 of plant glutamate receptors. Using the pGREAT vector designed for the expression of fusion proteins in plants, we show that a splicing variant of AtGLR3.5 targets the inner mitochondrial membrane, while the other variant localizes to chloroplasts. Mitochondria of knockout or silenced plants showed a strikingly altered ultrastructure, lack of cristae, and swelling. Furthermore, using a genetically encoded mitochondria-targeted calcium probe, we measured a slightly reduced mitochondrial calcium uptake capacity in the knockout mutant. These observations indicate a functional expression of AtGLR3.5 in this organelle. Furthermore, AtGLR3.5-less mutant plants undergo anticipated senescence. Our data thus represent, to our knowledge, the first evidence of splicing-regulated organellar targeting of a plant ion channel and identify the first cation channel in plant mitochondria from a molecular point of view.
Texto completo:
1
Bases de datos:
MEDLINE
Asunto principal:
Receptores de Glutamato
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Arabidopsis
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Empalme Alternativo
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Proteínas de Arabidopsis
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Mitocondrias
Tipo de estudio:
Prognostic_studies
Idioma:
En
Revista:
Plant Physiol
Año:
2015
Tipo del documento:
Article