Publication Information
Li et al., 2009
No external accession available
Abstract
Proteomics. 2009 Mar;9(6):1646-61. doi: 10.1002/pmic.200800420.
Phosphoproteomic analysis of ethylene-regulated protein phosphorylation in
etiolated seedlings of Arabidopsis mutant ein2 using two-dimensional separations
coupled with a hybrid quadrupole time-of-flight mass spectrometer.
Li H(1), Wong WS, Zhu L, Guo HW, Ecker J, Li N.
Author information:
(1)Department of Biology, The Hong Kong University of Science and Technology,
Hong Kong SAR, PR China.
Ethylene regulates a variety of stress responses and developmental adaptation in
plants. In the present study, the phosphoproteomics is adopted to investigate
the differential protein phosphorylation by ethylene in Arabidopsis
ethylene-insensitive 2 (ein2) mutant. A total of 224 phosphopeptides were
identified, of which 64 phosphopeptides were detected three or more times.
Ethylene induces a general reduction in phosphorylated proteins in ein2.
Totally, three ethylene-enhanced and three ethylene-repressible unique
phosphopeptides were identified, respectively. Classification of the cellular
functions of these phosphoproteins revealed that 55.5% of them are related to
signaling and gene expression. Peptide sequence alignment reveals two highly
conserved phosphorylation motifs, PRVD/GSx and SPDYxx. Alignment of these
phosphopeptides with Arabidopsis proteins reveals five phosphorylation motifs.
Both ethylene-enhanced and -repressible phosphopeptides present in these motifs.
EIL-1, ERF110 transcription factors and Hua enhancer 4 (HEN4) are predicted to
contain one of the phosphorylation motifs. The phosphorylation of the
motif-containing peptides has been validated by the in vitro kinase assays
coupled with MS analysis. The differential regulation of phosphorylation by
ethylene is substantiated by Western dot blot analysis. Taken together, these
results suggest that ethylene signals may be transduced by a phosphor-relay from
receptors to transcriptional events via both ein2-dependent and -independent
pathways.
DOI: 10.1002/pmic.200800420
PMID: 19253305 [Indexed for MEDLINE]
