The ubiquitin E3 ligase LOSS OF GDU2 Is required for GLUTAMINE DUMPER1-induced amino acid secretion in Arabidopsis

Réjane Pratelli, Damian D. Guerra, Shi Yu, Mark Wogulis, Edward Kraft, Wolf B. Frommer, Judy Callis, Guillaume Pilot

Research output: Contribution to journalArticle

22 Citations (Scopus)

Abstract

Amino acids serve as transport forms for organic nitrogen in the plant, and multiple transport steps are involved in cellular import and export. While the nature of the export mechanism is unknown, overexpression of GLUTAMINE DUMPER1 (GDU1) in Arabidopsis (Arabidopsis thaliana) led to increased amino acid export. To gain insight into GDU1's role, we searched for ethyl-methanesulfonate suppressor mutants and performed yeast-two-hybrid screens. Both methods uncovered the same gene, LOSS OF GDU2 (LOG2), which encodes a RING-type E3 ubiquitin ligase. The interaction between LOG2 and GDU1 was confirmed by glutathione S-transferase pull-down, in vitro ubiquitination, and in planta coimmunoprecipitation experiments. Confocal microscopy and subcellular fractionation indicated that LOG2 and GDU1 both localized to membranes and were enriched at the plasma membrane. LOG2 expression overlapped with GDU1 in the xylem and phloem tissues of Arabidopsis. The GDU1 protein encoded by the previously characterized intragenic suppressor mutant log1-1, with an arginine in place of a conserved glycine, failed to interact in the multiple assays, suggesting that the Gdu1D phenotype requires the interaction of GDU1 with LOG2. This hypothesis was supported by suppression of the Gdu1D phenotype after reduction of LOG2 expression using either artificial microRNAs or a LOG2 T-DNA insertion. Altogether, in accordance with the emerging bulk of data showing membrane protein regulation via ubiquitination, these data suggest that the interaction of GDU1 and the ubiquitin ligase LOG2 plays a significant role in the regulation of amino acid export from plant cells.

Original languageEnglish (US)
Pages (from-to)1628-1642
Number of pages15
JournalPlant Physiology
Volume158
Issue number4
DOIs
StatePublished - Apr 2012
Externally publishedYes

Fingerprint

ubiquitin-protein ligase
Ubiquitin-Protein Ligases
Arabidopsis
Ubiquitination
secretion
Amino Acids
amino acids
Ethyl Methanesulfonate
Phenotype
Phloem
Xylem
Plant Cells
Ligases
Ubiquitin
Glutathione Transferase
MicroRNAs
phenotype
Confocal Microscopy
ethyl methanesulfonate
mutants

ASJC Scopus subject areas

  • Plant Science
  • Genetics
  • Physiology

Cite this

Pratelli, R., Guerra, D. D., Yu, S., Wogulis, M., Kraft, E., Frommer, W. B., ... Pilot, G. (2012). The ubiquitin E3 ligase LOSS OF GDU2 Is required for GLUTAMINE DUMPER1-induced amino acid secretion in Arabidopsis. Plant Physiology, 158(4), 1628-1642. https://doi.org/10.1104/pp.111.191965

The ubiquitin E3 ligase LOSS OF GDU2 Is required for GLUTAMINE DUMPER1-induced amino acid secretion in Arabidopsis. / Pratelli, Réjane; Guerra, Damian D.; Yu, Shi; Wogulis, Mark; Kraft, Edward; Frommer, Wolf B.; Callis, Judy; Pilot, Guillaume.

In: Plant Physiology, Vol. 158, No. 4, 04.2012, p. 1628-1642.

Research output: Contribution to journalArticle

Pratelli, R, Guerra, DD, Yu, S, Wogulis, M, Kraft, E, Frommer, WB, Callis, J & Pilot, G 2012, 'The ubiquitin E3 ligase LOSS OF GDU2 Is required for GLUTAMINE DUMPER1-induced amino acid secretion in Arabidopsis', Plant Physiology, vol. 158, no. 4, pp. 1628-1642. https://doi.org/10.1104/pp.111.191965
Pratelli, Réjane ; Guerra, Damian D. ; Yu, Shi ; Wogulis, Mark ; Kraft, Edward ; Frommer, Wolf B. ; Callis, Judy ; Pilot, Guillaume. / The ubiquitin E3 ligase LOSS OF GDU2 Is required for GLUTAMINE DUMPER1-induced amino acid secretion in Arabidopsis. In: Plant Physiology. 2012 ; Vol. 158, No. 4. pp. 1628-1642.
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