Elicitine-membrane interaction is driven by a positive charge on the protein surface: Role of Lys13 residue in lipids loading and resistance induction
| Authors | |
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| Year of publication | 2011 |
| Type | Article in Periodical |
| Magazine / Source | Plant Physiology and Biochemistry |
| MU Faculty or unit | |
| Citation | |
| Doi | http://dx.doi.org/10.1016/j.plaphy.2011.01.008 |
| Field | Biochemistry |
| Keywords | Elicitins; Surface charge; Membrane interaction; Lipid binding; Resistance induction |
| Description | Elicitins are family of small proteins secreted by species of the pathogenic fungus Phytophthora inducing a defence reaction in plants. They contain a hydrophobic cavity capable of binding sterols and fatty acids, and on the basis of their pI they are classified as either alfa elicitins or more necrotizing beta elicitins. The residue Lys13 was previously identified as a key determinant of the necrotising activity of basic elicitins. In the present study we describe changes in the ability of cryptogein, a beta elicitin inducing a hypersensitive response in tobacco, to transfer sterols and fatty acids between micelles and liposomes upon Lys13Val mutation. We propose that the change in activity is influenced by the elimination of positive charge on the surface of cryptogein, which is significant for correct positioning of the protein during lipid loading, without adversely affecting the binding of sterol to the cavity of the protein. Compared to wild type cryptogein, mutation Lys13Val resulted in lowered expression of defence related genes and compromised resistance to P. parasitica. Furthermore, resistance induced by Lys13Val mutant was similar to that induced by acidic elicitin capsicein containing at amino position 13. valine. Determined results sustained a crucial role of positive lysine residues on the surface of basic elicitins and suggested their significant role in correct protein-membrane interaction and thus on their biological activity. |
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