Lipid helices formation in Bacillus
subtilis cell membrane
Barák I.1, K. Muchová1, N. Pavlendová1, Anthony J. Wilkinson2, J. Jamroškovič1
1Institute of Molecular Biology, Slovak Academy of Sciences, Bratislava
2Department of Chemistry, University of York, York, UK
The domains of different lipid composition are present in eukaryotic and prokaryotic cell membranes. Using membrane binding fluorescent dyes, we demonstrate previously, the presence of lipid spirals extending along the long-axis of cells of the rod-shaped bacterium B. subtilis (1). These data indicate a higher level of membrane lipid organization than previously observed. Little is known however of the origin of these helical structures.
Principally, there are at least three main specifically localized molecular structures in the membrane or close proximity to it what can help to form or influence the formation of lipid helixes. In our work we have focused on analyzing these lipid structures in correlation with other above mentioned helical structures in the cell membrane or its close proximity. We were analyzing lipid domains by using lipid specific dyes in protoplasted cells, in Mbl, MreB and MreBH mutant strains. We have used FRAP and FRET experiments to determine dynamics of lipid domains and co-localization of lipid dyes with GFP fused proteins, respectively.
We have also studied the role of lipid helices in cell division by directing the Min system to the helices from pole to pole. We inspected cell division when E. coli Min-system was introduced into B. subtilis cells. We show that MinDEc can partially substitute function of its B. subtilis protein counterpart (2). Additionally, we observed dynamic behavior of MinDEc and MinE in B. subtilis when expressed together. All these findings indicate that these two Min systems resemble each other more than was thought previously.
1. Barak I, Muchova K, Wilkinson AJ, O'Toole PJ, Pavlendova N (2008) Mol. Microbiol. 68: 1315-1327.
2. Pavlendova N, Muchova K, Barak I (2010) Expression of Escherichia coli Min system in Bacillus subtilis and its effect on cell division. FEMS Microbiol. Letters 302: 58-68.
This work was supported by the grant APVT-51-027804, No. ESF-EC-0106, LPP-0218-06 and VEGA grant 2/0016/10 from the Slovak Academy of Sciences and The Wellcome Trust Grant 082829/Z/07/Z.