Please use this identifier to cite or link to this item: http://hdl.handle.net/10261/37950
Share/Impact:
Title: Fungal cell wall phosphomannans facilitate the toxic activity of a plant PR-5 protein
Authors: Ibeas, José I., Lee, Hyeseung, Damsz, Barbara, Prasad, Doddananjappa T., Pardo, José M., Hasegawa, Paul M., Bressan, Ray A., Narasimhan, Meena L.
Keywords: Cell wall
Fungal
Mannan
Pathogenesis-related protein
Saccharomyces cerevisiae
Thamatin-like
Issue Date: Aug-2000
Publisher: Wiley-Blackwell
Abstract: Osmotin is a plant PR-5 protein. It has a broad spectrum of antifungal activity, yet also exhibits specificity for certain fungal targets. The structural bases for this specificity remain unknown. We show here that full sensitivity of Saccharomyces cerevisiae cells to the PR-5 protein osmotin is dependent on the function of MNN2, MNN4 and MNN6. MNN2 is an α-1,2-mannosyltransferase catalyzing the addition of the first mannose to the branches on the poly l,6-mannose backbone of the outer chain of cell wall N-linked mannans. MNN4 and MNN6 are required for the transfer of mannosylphosphate to cell wall mannans. Null mnn2, mnn4 or mnn6 mutants lack phosphomannans and are defective in binding osmotin to the fungal cell wall. Both antimannoprotein antibody and the cationic dye alcian blue protect cells against osmotin cytotoxicity. MNN1 is an α-1,3-mannosyltransferase that adds the terminal mannose to the outer chain branches of N-linked mannan, masking mannosylphosphate. Null mnn1 cells exhibit enhanced osmotin binding and sensitivity. Several cell wall mannoproteins can bind to immobilized osmotin, suggesting that their polysaccharide constituent determines osmotin binding. Our results demonstrating a causal relationship between cell surface phosphomannan and the susceptibility of a yeast strain to osmotin suggest that cell surface polysaccharides of invading pathogens control target specificity of plant PR-5 proteins.
Description: 9 pages, 6 figures, 1 table, 35 references.
Publisher version (URL): http://dx.doi.org/10.1046/j.1365-313x.2000.00792.x
URI: http://hdl.handle.net/10261/37950
ISSN: 0960-7412
???metadata.dc.identifier.doi???: 10.1046/j.1365-313x.2000.00792.x
Citation: Plant Journal 23 (3): 375-383 (2000)
Appears in Collections:(IRNAS) Artículos

Files in This Item:
There are no files associated with this item.
Show full item record
 
CSIC SFX LinksSFX Query


Items in Digital.CSIC are protected by copyright, with all rights reserved, unless otherwise indicated.