Összes szerző

Robert C. Robinson

az alábbi absztraktok szerzői között szerepel:

Barkó Szilvia
Phalloidin as a bacterial actin-labeling agent

Aug 28 - szerda

13:30 – 15:30

II. Poszterszekció

P45

Phalloidin as a bacterial actin-labeling agent 

Szilvia Barkó1,5, Beáta Longauer1, Emőke Bódis1, Dávid Szatmári1, Zoltán Ujfalusi1, Robert C. Robinson2,3 and Miklós Nyitrai1,4,5

1Department of Biophysics, Medical School, University of Pécs, Szigeti str. 12, Pécs, H-7624, Hungary

2Research Institute for Interdisciplinary Science, Okayama University, Okayama 700-8530, Japan.

3VISTEC, Thailand

4MTA-PTE Nuclear-Mitochondrial Interactions Research Group, Szigeti str. 12, Pécs, H-7624, Hungary

5Szentágothai Research Center, University of Pécs, Hungary

The visualization of subcellular objects by microscopy is one of the most important tools in biological studies. Some subcellular objects, due to their smallness in size, can challenge the physical barrier of resolution for microscopy. Although this area of biophysics is rapidly evolving limitations remain. The internal organization of eukaryotic cells is becoming better characterized due to the wealth of visualization probes that are available. Prokaryotes are smaller and their internal cellular organization has been resolved to a lesser extent. One recent study highlights one problem that there are only very few optical compounds that can be applied to visualize components of bacterial cells. The visualization of cytoskeletal components has a long history. For example, eukaryotic actin F-actin has been visualized in many studies by fluorescently conjugated phalloidin. This peptide is a toxin from the mushroom Amanita phalloides, which specifically binds to F-actin. However, in order to visualize F-actin in vivo, the cell membrane must be permeabilized because phalloidin is a membrane-impenetrable compound consequently it cannot enter the cell.

Two decades ago, phalloidin was reported to bind to bacterial actin-like proteins. At that time, microscopy technology had not developed sufficiently to solve the fine structure of the fluorescently-labelled cytoskeleton organization, and only low resolution images were obtained. Here, we used fluorescently-conjugated phalloidin to visualize MreB in vitro, and determine the in vivo localization of MreB in Gram positive and Gram negative cells. We tested the effects of phalloidin on the dynamics of MreB and on the viability of bacterial cells. By contrast to the harmful effects of phalloidin on actin dynamics and eukaryotic cell viability, phalloidin did not affect MreB dynamics of bacterial growth rates, however it did induce a morphology change to longer cell chain lengths.

Acknowledgement

OTKA-107776: An anchor biological systems characteristics: the structural and functional properties of bacterial filaments.