Department of Chemistry
Seminar
Sacha Baginsky
Martin-Luther-Universität Halle-Wittenberg, Institut für Biochemie und Biotechnologie, Abteilung Pflanzenbiochemie
Title:
Functional characterization of plant proteome dynamics
Place : Lilla hörsalen, KB3A9, KBC
Host Christiane Funk
Abstract:
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.
Sacha Baginsky
Martin-Luther-Universität Halle-Wittenberg, Institut für Biochemie und Biotechnologie, Abteilung Pflanzenbiochemie, Weinbergweg 22 (Biozentrum),
06120 Halle (Saale)
Email:
Department of Chemistry
Seminar
Beverley Green
University of British Columbia, Vancouver, Canada
Title: Algal genomics and the evolution of light-harvesting antennae
Host: Christiane Funk
Place: Lilla Hörsalen, KB3A9, KBC
Abstract:
The ocean is the new frontier in genomics research! The marine algae are particularly important because of their influence on global climate as well as their major contribution to the oceanic food web. The recently sequenced genomes of a number of these algae have illuminated the wide range of photosynthetic biodiversity in the ocean. Particularly interesting are the algae with chlorophyll a/c light-harvesting antennas, such as the diatoms and brown algae, which acquired their plastids by secondary endosymbiosis, and have derived new varieties of light-harvesting antennas.
Seminar
professor Kazuya Kikuchi
Osaka University
Graduate School of Engineering
WPI-Immunology Frontier Research Center
Osaka, Japan
Title: Design, synthesis and biological application of in vivo imaging probes with tunable chemical switches
Host: Gunnar Öquist
Place: KBC, Large Lecture hall "Stora hörsalen"
Abstract:
One of the great challenges in the post-genome era is to clarify the biological significance of intracellular molecules directly in living cells. If we can image a molecule in action, it is possible to acquire biological information, which is unavailable if we deal with cell homogenates. One possible approach is to design and synthesize chemical probes that can convert biological information to chemical output. Protein fluorescent labeling provides an attractive approach to study the localization and function of proteins in living cells. Recently, a specific pair of a protein tag and its ligand has been utilized to visualize a protein of interest (POI). In this method, a POI is fused with a protein tag and the tag is labeled with the ligand connected to a fluorescent molecule. The advantage of this protein labeling system is that a variety of fluorescent molecules are potentially available as labeling reagents, and that the protein tag is conditionally labeled with its fluorescent ligand. I have designed a protein labeling system that allows fluorophores to be linked to POI. The protein tag (BL-tag) is a mutant class A ?-lactamase (TEM-1) modified to be covalently bound to the designed specific labeling probes and the labeling probes is consisted with a ?-lactam ring (ampicillin, cephalosporin) attached to various fluorophores. A fluorogenetic labeling system can be designed using the unique property of cephalosporin, which release leaving group by subsequent reaction after opening the lactam ring. For further sophisticated application, multicolor imaging was done by adopting the colorful fluorophores.
Workshop on Plant Proteomics with Focus on Redox Proteomics
The workshop is organized by the KBC Proteomics Facility in collaboration with the International Plant Proteomics Organization (INPPO).
Speakers:
Ian Max Møller (Aarhus University, Denmark)
Per Hägglund (Technical University of Denmark)
Bob Buchanan (University of California, Berkeley)
Thomas Kieselbach (Umeå University)
The workshop will give an introduction into the chemistry of post-translational protein modifications by carbonylation and thiol oxidation and present methods to study them by proteomics. As for carbonylation, a brief introduction to the analysis of stress-induced ROS production and metal-catalyzed protein oxidation and will be given and the consequences of irreversible protein oxidation will be discussed. As for thiol oxidation different, the workshop will provide an introduction to different techniques to study target proteins of thioredoxin (Trx) using mass spectrometry and gel based approaches. This includes the use of ICAT reagents for Trx-target identification and the analysis of Trx-targets using 2-D fluorescence electrophoresis and affinity chromatography by means of monocysteinic Trx-ligands. The opportunities and limitations of these techniques will be discussed using examples from different research projects.
Please register by sending an email to:
Location: KBF 31