Publication Information
Kline et al., 2010
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Abstract
Proc Natl Acad Sci U S A. 2010 Sep 7;107(36):15986-91. doi:
10.1073/pnas.1007879107. Epub 2010 Aug 23.
In planta changes in protein phosphorylation induced by the plant hormone
abscisic acid.
Kline KG(1), Barrett-Wilt GA, Sussman MR.
Author information:
(1)Biotechnology Center, Department of Biochemistry, University of Wisconsin,
Madison, 53706, USA.
Abscisic acid (ABA) is a hormone that controls seed dormancy and germination as
well as the overall plant response to important environmental stresses such as
drought. Recent studies have demonstrated that the ABA-bound receptor binds to
and inhibits a class of protein phosphatases. To identify more broadly the
phosphoproteins affected by this hormone in vivo, we used (14)N/(15)N metabolic
labeling to perform a quantitative untargeted mass spectrometric analysis of the
Arabidopsis thaliana phosphoproteome following ABA treatment. We found that 50
different phosphopeptides had their phosphorylation state significantly altered
by ABA over a treatment period lasting 5-30 min. Among these changes were
increases in phosphorylation of subfamily 2 SNF1-related kinases and
ABA-responsive basic leucine zipper transcription factors implicated in ABA
signaling by previous in vitro studies. Furthermore, four members of the
aquaporin family showed decreased phosphorylation at a carboxy-terminal serine
which is predicted to cause closure of the water-transporting aquaporin gate,
consistent with ABA's role in ameliorating the effect of drought. Finally, more
than 20 proteins not previously known to be involved with ABA were found to have
significantly altered phosphorylation levels. Many of these changes are
phosphorylation decreases, indicating that an expanded model of ABA signaling,
beyond simple phosphatase inhibition, may be necessary. This quantitative
proteomics dataset provides a more comprehensive, albeit incomplete, view both
of the protein targets whose biochemical activities are likely to be controlled
by ABA and of the nature of the emerging phosphorylation and dephosphorylation
cascades triggered by this hormone.
DOI: 10.1073/pnas.1007879107
PMCID: PMC2936636
PMID: 20733066 [Indexed for MEDLINE]
Conflict of interest statement: The authors declare no conflict of interest.
