Department of Chemistry
Martin-Luther-Universität Halle-Wittenberg, Institut für Biochemie und Biotechnologie, Abteilung Pflanzenbiochemie
Functional characterization of plant proteome dynamics
Place : Lilla hörsalen, KB3A9, KBC
Host Christiane Funk
Different functional proteomics tools are now available that enable the quantitative characterization of proteome dynamics and the mapping of posttranslational modifications. We report here examples how we used these tools to characterize the functional proteome of Arabidopsis and rice cell organelles, with a focus on the plant-specific plastids. We analyzed the Arabidopsis proteome at genome-scale and provide quantitative information about organellar proteomes in different plant organs by "normalized spectral counting" (Science, 320: 938-41). For a functional characterization of plastid protein import, we analyzed the proteomes of plastid protein import mutants and searched for N-terminal acetylated peptides in genome-scale WT, ppi1 and ppi2 proteomics data. These analyses revealed the accumulation of precursor proteins in the cytosol of the import mutants. In order to assess the short-term regulation of the chloroplast proteome in response to environmental signals, we analyzed the chloroplast phosphoproteome and characterized its dynamics during a circadian cycle (Plant Physiol, 150: 889-903). Differential protein phosphorylation was assessed by relative protein quantification with "extracted ion chromatograms". We present here our data, comment on reliability and reproducibility and propose strategies to increase both at a reasonable cost.
Martin-Luther-Universität Halle-Wittenberg, Institut für Biochemie und Biotechnologie, Abteilung Pflanzenbiochemie, Weinbergweg 22 (Biozentrum),
06120 Halle (Saale)