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Identification in pea seed mitochondria of a late-embryogenesis abundant protein able to protect enzymes from drying.
Grelet J., Benamar A., Teyssier E., Avelange-Macherel M.-H., Grunwald D., Macherel D.
Plant Physiology 137, 1 (2005) 157-67 - http://www.hal.inserm.fr/inserm-00764327
Identification in pea seed mitochondria of a late-embryogenesis abundant protein able to protect enzymes from drying.
Johann Grelet1, Abdelilah Benamar1, Emeline Teyssier1, Marie-Hélène Avelange-Macherel1, Didier Grunwald2, David Macherel () 1
1 :  PMS - Physiologie Moléculaire des Semences
Agrocampus Ouest – Institut national de la recherche agronomique (INRA) : UMR1191
16 Boulevard Lavoisier 49045 Angers cedex 01
2 :  Laboratoire Canaux Ioniques et Signalisation
INSERM : EMI9931 – Département Réponse et Dynamique Cellulaire (DRDC) – Commissariat à l'Énergie Atomique et aux Énergies Alternatives (CEA) - Grenoble
Bât. C3 - 17 Rue des Martyrs 38054 Grenoble Cedex 09
ANTE-INSERM U836, équipe 4, Muscles et pathologies
Late-embryogenesis abundant (LEA) proteins are hydrophilic proteins that accumulate to a high level in desiccation-tolerant tissues and are thus prominent in seeds. They are expected to play a protective role during dehydration; however, functional evidence is scarce. We identified a LEA protein of group 3 (PsLEAm) that was localized within the matrix space of pea (Pisum sativum) seed mitochondria. PsLEAm revealed typical LEA features such as high hydrophilicity and repeated motifs, except for the N-terminal transit peptide. Most of the highly charged protein was predicted to fold into amphiphilic alpha-helixes. PsLEAm was expressed during late seed development and remained in the dry seed and throughout germination. Application of the stress hormone abscisic acid was found to reinduce the expression of PsLEAm transcripts during germination. PsLEAm could not be detected in vegetative tissues; however, its expression could be reinduced in leaves by severe water stress. The recombinant PsLEAm was shown to protect two mitochondrial matrix enzymes, fumarase and rhodanese, during drying in an in vitro assay. The overall results constitute, to our knowledge, the first characterization of a LEA protein in mitochondria and experimental evidence for a beneficial role of a LEA protein with respect to proteins during desiccation.
Sciences du Vivant/Biologie cellulaire

Articles dans des revues avec comité de lecture
Plant Physiology (Plant Physiol)
Publisher American Society of Plant Biologists
ISSN 0032-0889 (eISSN : 0032-0889)

Amino Acid Sequence – Gene Expression Regulation – Plant – Mitochondria – Molecular Sequence Data – Peas – Plant Proteins – Seeds – Water – Amino Acid Sequence
This work was supported by the Contrat de Plan Etat-Re'gion Pays-de-la-Loire Semences and by the Institut National de la Recherche Agronomique/Re'gion Pays-de-la-Loire (doctoral fellowship to J.G.).
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