Phosphoproteins regulated by heat stress in rice leaves

Abstract

BackgroundHigh temperature is a critical abiotic stress that reduces crop yield and quality. Rice (Oryza sativa L.) plants remodel their proteomes in response to high temperature stress. Moreover, phosphorylation is the most common form of protein post-translational modification (PTM). However, the differential expression of phosphoproteins induced by heat in rice remains unexplored.MethodsPhosphoprotein in the leaves of rice under heat stress were displayed using two-dimensional electrophoresis (2-DE) and Pro-Q Diamond dye. Differentially expressed phosphoproteins were identified by MALDI-TOF-TOF-MS/MS and confirmed by Western blotting.ResultsTen heat-phosphoproteins were identified from twelve protein spots, including ribulose bisphos-phate carboxylase large chain, 2-Cys peroxiredoxin BAS1, putative mRNA binding protein, Os01g0791600 protein, OSJNBa0076N16.12 protein, putative H(+)-transporting ATP synthase, ATP synthase subunit beta and three putative uncharacterized proteins. The identification of ATP synthase subunit beta was further validated by Western-blotting. Four phosphorylation site predictors were also used to predict the phosphorylation sites and the specific kinases for these 10 phosphoproteins.ConclusionHeat stress induced the dephosphorylation of RuBisCo and the phosphorylation of ATP-β, which decreased the activities of RuBisCo and ATP synthase. The observed dephosphorylation of the mRNA binding protein and 2-Cys peroxiredoxin may be involved in the transduction of heat-stress signaling, but the functional importance of other phosphoproteins, such as H+-ATPase, remains unknown.

The conformational bases for the two functionalities of 2-cysteine peroxiredoxins as peroxidase and chaperone

“…Replacing the hydrophobic Phe by a charged residue in this interface should impede the interaction in the dimer–dimer interface and stabilize the dimeric form (F84R). Recently, it was found that Oryza sativa 2-CysPrx is phosphorylated (Chen et al , 2011). Plant 2-CysPrxs have the conserved threonine residue T92.…”

“…Furthermore, previous studies have suggested that pH, temperature, and salt concentrations influence the conformation (Bernier-Villamor et al , 2004). In a proteomics approach, rice 2-CysPrx was detected as being reversibly phosphorylated, with heat as the trigger of dephosphorylation (Chen et al , 2011). Introduction of a negative charge at Thr92 mimicking phosphorylation increased the sensitivity of 2-CysPrx to hyperoxidation.…”

Cardiac phosphoproteome reveals cell signaling events involved in doxorubicin cardiotoxicity

“…In fact, the detection limit of Pro-Q Diamond is as low as a few ng [28]. Second, specificity of Pro-Q Diamond staining was directly confirmed by comparing non-dephosphorylated and dephosphorylated samples or by comparison with autoradiograms after 32 P-labeling of samples [29][30][31][32][33]. Third, our preliminary experiments showed that band patterns in 1D-gels revealed by Pro-Q Diamond staining correspond to those revealed by immunoblots against P-Ser, P-Tyr and P-Thr (not shown).…”

Protein complex and proteomic profile in the roots of Oryza sativa L. in response to cadmium toxicity

“…Three independent sets of ontologies were used to describe a gene product, the biological process, the molecular function and the cellular compartment (Chen et al 2011).…”