Plant Molecular Biology

, Volume 73, Issue 3, pp 325–338

TMKP1 is a novel wheat stress responsive MAP kinase phosphatase localized in the nucleus

  • Ikram Zaïdi
  • Chantal Ebel
  • Majdi Touzri
  • Etienne Herzog
  • Jean-Luc Evrard
  • Anne Catherine Schmit
  • Khaled Masmoudi
  • Moez Hanin
Article

DOI: 10.1007/s11103-010-9617-4

Cite this article as:
Zaïdi, I., Ebel, C., Touzri, M. et al. Plant Mol Biol (2010) 73: 325. doi:10.1007/s11103-010-9617-4

Abstract

The regulation of plant signalling responses by Mitogen-Activated Protein Kinases (MAPKs)-mediated protein phosphorylation is well recognized. MAP kinase phosphatases (MKPs) are negative regulators of MAPKs in eukaryotes. We report here the identification and the characterization of TMKP1, the first wheat MKP (Triticum turgidum L. subsp. Durum). Expression profile analyses performed in two durum wheat cultivars showing a marked difference in salt and drought stress tolerance, revealed a differential regulation of TMKP1. Under salt and osmotic stress, TMKP1 is induced in the sensitive wheat variety and repressed in the tolerant one. A recombinant TMKP1 was shown to be an active phosphatase and capable to interact specifically with two wheat MAPKs (TMPK3 and TMPK6). In BY2 tobacco cells transiently expressing GFP::TMKP1, the fusion protein was localized into the nucleus. Interestingly, the deletion of the N-terminal non catalytic domain results in a strong accumulation of the truncated fusion protein in the cytoplasm. In addition, when expressed in BY2 cells, TMPK3 and TMPK6 fused to red fluorescent protein (RFP) were shown to be present predominantly in the nucleus. Surprisingly, when co-expressed with the N-terminal truncated TMKP1 fusion protein; both kinases are excluded from the nuclear compartment and accumulate in the cytoplasm. This strongly suggests that TMKP1 interacts in vivo with TMPK3 and TMPK6 and controls their subcellular localization. Taken together, our results show that the newly isolated wheat MKP might play an active role in modulating the plant cell responses to salt and osmotic stress responses.

Keywords

Abiotic stress Durum wheat MAP kinase MAP kinase phosphatase GFP RFP Nuclear localization 

Copyright information

© Springer Science+Business Media B.V. 2010

Authors and Affiliations

  • Ikram Zaïdi
    • 1
  • Chantal Ebel
    • 1
  • Majdi Touzri
    • 1
  • Etienne Herzog
    • 2
  • Jean-Luc Evrard
    • 2
  • Anne Catherine Schmit
    • 2
  • Khaled Masmoudi
    • 1
  • Moez Hanin
    • 1
  1. 1.Laboratoire de Génétique Moléculaire des Plantes du Centre de Biotechnologie de SfaxSfaxTunisia
  2. 2.Institut de Biologie Moléculaire des Plantes du CNRSUniversité de StrasbourgStrasbourg CedexFrance