Plasma membrane association of three classes of bacterial toxins is mediated by a basic-hydrophobic motif
Article first published online: 29 NOV 2011
© 2011 Blackwell Publishing Ltd
Volume 14, Issue 2, pages 286–298, February 2012
How to Cite
Geissler, B., Ahrens, S. and Satchell, K. J. F. (2012), Plasma membrane association of three classes of bacterial toxins is mediated by a basic-hydrophobic motif. Cellular Microbiology, 14: 286–298. doi: 10.1111/j.1462-5822.2011.01718.x
- Issue published online: 18 JAN 2012
- Article first published online: 29 NOV 2011
- Accepted manuscript online: 1 NOV 2011 08:00AM EST
- Received 21 July, 2011; revised 21 October, 2011; accepted 25 October, 2011.
Plasma membrane targeting is essential for the proper function of many bacterial toxins. A conserved fourhelical bundle membrane localization domain (4HBM) was recently identified within three diverse families of toxins: clostridial glucosylating toxins, MARTX toxins and Pasteurella multocida-like toxins. When expressed in tissue culture cells or in yeast, GFP fusions to at least one 4HBM from each toxin family show significant peripheral membrane localization but with differing profiles. Both in vivo expression and in vitro binding studies reveal that the ability of these domains to localize to the plasma membrane and bind negatively charged phospholipids requires a basic-hydrophobic motif formed by the L1 and L3 loops. The different binding capacity of each 4HBM is defined by the hydrophobicity of an exposed residue within the motif. This study establishes that bacterial effectors utilize a normal host cell mechanism to locate the plasma membrane where they can then access their intracellular targets.