Aktuelles

 

    Proteomics of FACS-sorted heterogeneous Corynebacterium glutamicum populations.
    Harst A, Albaum SP, Bojarzyn T, Trötschel C#, Poetsch A# (#co-corresponding authors). J Proteomics. 2017;doi: 10.1016/j.jprot.2017.03.010.

    Icon for Journal of Proteomics
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      Abstract The metabolic status of individual cells in microbial cultures can differ, being relevant for biotechnology, environmental and medical microbiology. However, it is hardly understood in molecular detail due to limitations of current analytical tools. Here, we demonstrate that FACS in combination with proteomics can be used to sort and analyze cell populations based on their metabolic state. A previously established GFP reporter system was used to detect and sort single Corynebacterium glutamicum cells based on the concentration of branched chain amino acids (BCAA) using FACS. A proteomics workflow optimized for small cell numbers was used to quantitatively compare proteomes of a ΔaceE mutant, lacking functional pyruvate dehydrogenase (PD), and the wild type. About 800 proteins could be quantified from 1,000,000 cells. In the ΔaceE mutant BCAA production was coordinated with upregulation of the glyoxylate cycle and TCA cycle to counter the lack of acetyl CoA resulting from the deletion of aceE.

     

  • Christian Trötschel hält einen Vortrag auf der HUPO 2016 in Taipeh, Taiwan.

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      Vom 18. bis 21.09.16 fand der 15. Human Proteome Organization (HUPO) Weltkongress in Taipeh (Taiwan) statt. Im Rahmen dieser Tagung hielt Christian Trötschel einen Kurzvortrag über "Proteome Turnover Analysis Reveals Substrates and Physiological Role of Membrane Proteases".

     

  • Christian Trötschel ist für 5 Wochen an der Universität Mar del Plata, Argentinien.

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      Im Rahmen des BMBF geförderten Projektes "The role of membrane integral proteases for proteome dynamics in microorganisms: A comparative proteome turnover approach" in Zusammenarbeit mit Prof. Rosana E. De Castro arbeitet Christian Trötschel vom 15.11.15 bis 18.12.15 am Institut IIB-CONICET-UNMDP in Mar del Plata, Argentinien. Am 01.12.15 hält Christian Trötschel im dortigen Institutsseminar einen Vortrag über Corynebacterium- und Spermien-Proteomik.

     

  • Andreas Harst erhält einen Posterpreis auf der IZKF-Tagung.

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      Am 03.12.15 fand die "Münster Conference on Biomolecule Analysis" des Interdisziplinären Zentrums für Klinische Forschung (IZKF) Münster statt. Im Rahmen dieser Veranstaltung erhielt Andreas Harst für seinen Beitrag "Accurate determination of cellular protein copy numbers for a membrane-localized signal transduction network" einen der beiden Posterpreise.

     

  • Andreas Harst hält einen Vortrag auf einer Tagung zu Einzelzell-Analytik.

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      Vom 19. bis 22.07.2015 findet in Retz (Österreich) die "6th International Conference on Analysis of MICROBIAL CELLS at the SINGLE CELL LEVEL" statt. Aus den eingereichten Abstracts wurde Andreas Harst ausgewählt, einen Vortrag zum Thema "Proteomic profiling of FACS sorted, small Corynebacterium glutamicum leucine producer populations" zu halten.

     

  • The CatSper channel controls chemosensation in sea urchin sperm.
    Seifert R, Flick M, Bönigk W, Alvarez L, Trötschel C, Poetsch A, Müller A, Goodwin N, Pelzer P, Kashikar ND, Kremmer E, Jikeli J, Timmermann B, Kuhl H, Fridman D, Windler F, Kaupp UB, Strünker T. EMBO J. 2015;34:379-392.

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      Abstract Sperm guidance is controlled by chemical and physical cues. In many species, Ca2+ bursts in the flagellum govern navigation to the egg. In Arbacia punctulata, a model system of sperm chemotaxis, a cGMP signaling pathway controls these Ca2+ bursts. The underlying Ca2+ channel and its mechanisms of activation are unknown. Here, we identify CatSper Ca2+ channels in the flagellum of A. punctulata sperm. We show that CatSper mediates the chemoattractant-evoked Ca2+ influx and controls chemotactic steering; a concomitant alkalization serves as a highly cooperative mechanism that enables CatSper to transduce periodic voltage changes into Ca2+ bursts. Our results reveal intriguing phylogenetic commonalities but also variations between marine invertebrates and mammals regarding the function and control of CatSper. The variations probably reflect functional and mechanistic adaptations that evolved during the transition from external to internal fertilization.

     

  • Current approaches and challenges in targeted absolute quantification of membrane proteins.
    Trötschel C, Poetsch A. Proteomics. 2015;15:915-929.

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      Abstract Experimental determination of absolute protein amounts is becoming increasingly important for the establishment and validation of biomarkers, and systems biology approaches aimed at a quantitative description of a biological process. Residing at compartmental or cellular barriers, and acting as prominent drug targets, integral membranes proteins, being completely embedded in the lipid bilayer, possess characteristic physicochemical properties and are often in low abundance. These features challenge the quantification with targeted MS and the ability to accurately determine the amount of membrane proteins with high sensitivity. This review summarizes the current status of targeted membrane protein quantification with emphasis on sample preparation beforehand MS. From the beginning to the end of a usual sample preparation workflow, consisting essentially of reference point selection, cell lysis, digestion, and addition of suitable isotope-labeled standards, general and particular challenges for membrane proteins will be discussed step by step. Based on the presentation of current achievements, possible measures to better address these challenges and future avenues of targeted membrane proteomics are presented.

     

  • Christian Trötschel erhält einen Posterpreis auf dem getgeoweb-Workshop 2014.

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      Vom 26. bis 29.10.2014 trafen sich etwa 90 Wissenschaftler im Rahmen des getgeoweb-Workshops an der TU Freiberg, um aktuelle Themen der Geobiotechnologie und der weißen Biotechnologie zu präsentieren und diskutieren. Im Rahmen dieser Veranstaltung erhielt Christian Trötschel für seinen Beitrag "Comparative shotgun proteomics to uncover physiological differences in microorganisms" einen von Thermo Scientific gesponserten Posterpreis.

     

  • High density and ligand affinity confer ultrasensitive signal detection by a guanylyl cyclase chemoreceptor.
    Pichlo M, Bungert-Plümke S, Weyand I, Seifert R, Bönigk W, Strünker T, Kashikar ND, Goodwin N, Müller A, Körschen HG, Collienne U, Pelzer P, Van Q, Enderlein J, Klemm C, Krause E, Trötschel C, Poetsch A, Kremmer E, Kaupp UB. J Cell Biol. 2014;206:541-557.

    Icon for The Journal of Cell Biology
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      Abstract Guanylyl cyclases (GCs), which synthesize the messenger cyclic guanosine 3',5'-monophosphate, control several sensory functions, such as phototransduction, chemosensation, and thermosensation, in many species from worms to mammals. The GC chemoreceptor in sea urchin sperm can decode chemoattractant concentrations with single-molecule sensitivity. The molecular and cellular underpinnings of such ultrasensitivity are not known for any eukaryotic chemoreceptor. In this paper, we show that an exquisitely high density of 3 × 105 GC chemoreceptors and subnanomolar ligand affinity provide a high ligand-capture efficacy and render sperm perfect absorbers. The GC activity is terminated within 150 ms by dephosphorylation steps of the receptor, which provides a means for precise control of the GC lifetime and which reduces "molecule noise." Compared with other ultrasensitive sensory systems, the 10-fold signal amplification by the GC receptor is surprisingly low. The hallmarks of this signaling mechanism provide a blueprint for chemical sensing in small compartments, such as olfactory cilia, insect antennae, or even synaptic boutons.

     



 

Kontakt

Dr. Christian Trötschel



Ruhr-Universität Bochum
LS Biochemie der Pflanzen
Universitätsstraße 150
44780 Bochum

Raum: ND 3/130
Tel.: +49 234 32-24535
Fax : +49 234 32-14322
christian.troetschel@rub.de