Processing and Secretion of a Virally Encoded Antifungal Toxin in Transgenic Tobacco Plants: Evidence for a Kex2p Pathway in Plants

Overview

Journal Plant Cell

Publisher Oxford University Press

Specialties Biology
Cell Biology

Date 1995 Jun 1

PMID 7647561

Citations 16

Authors

H Kinal

C M Park

J O Berry

Y Koltin

J A Bruenn

Affiliations

Soon will be listed here.

Abstract

Ustilago maydis is a fungal pathogen of maize. Some strains of U. maydis encode secreted polypeptide toxins capable of killing other susceptible strains of U. maydis. We show here that one of these toxins, the KP6 killer toxin, is synthesized by transgenic tobacco plants containing the viral toxin cDNA under the control of a cauliflower mosaic virus promoter. The two components of the KP6 toxin, designated alpha and beta, with activity and specificity identical to those found in toxin secreted by U. maydis cells, were isolated from the intercellular fluid of the transgenic tobacco plants. The beta polypeptide from tobacco was identical in size and N-terminal sequence to the U. maydis KP6 beta polypeptide. Processing of the KP6 preprotoxin in U. maydis requires a subtilisin-like processing protease, Kex2p, which is present in both animal and fungal cells and is required for processing of (among other things) small secreted polypeptide hormones and secreted toxins. Our findings present evidence for Kex2p-like processing activity in plants. The systemic production of this viral killer toxin in crop plants may provide a new method of engineering biological control of fungal pathogens in crop plants.

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References

Brenner C, Fuller R . Structural and enzymatic characterization of a purified prohormone-processing enzyme: secreted, soluble Kex2 protease. Proc Natl Acad Sci U S A. 1992; 89(3):922-6. PMC: 48357. DOI: 10.1073/pnas.89.3.922. View

Thomas L, Leduc R, Thorne B, Smeekens S, Steiner D, Thomas G . Kex2-like endoproteases PC2 and PC3 accurately cleave a model prohormone in mammalian cells: evidence for a common core of neuroendocrine processing enzymes. Proc Natl Acad Sci U S A. 1991; 88(12):5297-301. PMC: 51859. DOI: 10.1073/pnas.88.12.5297. View

Koltin Y, Day P . Inheritance of killer phenotypes and double-stranded RNA in Ustilago maydis. Proc Natl Acad Sci U S A. 1976; 73(2):594-8. PMC: 335957. DOI: 10.1073/pnas.73.2.594. View

Kinal H, Tao J, Bruenn J . An expression vector for the phytopathogenic fungus, Ustilago maydis. Gene. 1991; 98(1):129-34. DOI: 10.1016/0378-1119(91)90115-r. View

Martinac B, Zhu H, Kubalski A, Zhou X, Culbertson M, Bussey H . Yeast K1 killer toxin forms ion channels in sensitive yeast spheroplasts and in artificial liposomes. Proc Natl Acad Sci U S A. 1990; 87(16):6228-32. PMC: 54506. DOI: 10.1073/pnas.87.16.6228. View

von Heijne G . A new method for predicting signal sequence cleavage sites. Nucleic Acids Res. 1986; 14(11):4683-90. PMC: 311474. DOI: 10.1093/nar/14.11.4683. View

Berry J, Nikolau B, Carr J, Klessig D . Transcriptional and post-transcriptional regulation of ribulose 1,5-bisphosphate carboxylase gene expression in light- and dark-grown amaranth cotyledons. Mol Cell Biol. 1985; 5(9):2238-46. PMC: 366949. DOI: 10.1128/mcb.5.9.2238-2246.1985. View

Hayflick J, Wolfgang W, Forte M, Thomas G . A unique Kex2-like endoprotease from Drosophila melanogaster is expressed in the central nervous system during early embryogenesis. J Neurosci. 1992; 12(3):705-17. PMC: 6576047. View

von Heijne G . Signal sequences. The limits of variation. J Mol Biol. 1985; 184(1):99-105. DOI: 10.1016/0022-2836(85)90046-4. View

10.

Koltin Y, Day P . Specificity of Ustilago maydis killer proteins. Appl Microbiol. 1975; 30(4):694-6. PMC: 187249. DOI: 10.1128/am.30.4.694-696.1975. View

11.

Schaller A, Ryan C . Identification of a 50-kDa systemin-binding protein in tomato plasma membranes having Kex2p-like properties. Proc Natl Acad Sci U S A. 1994; 91(25):11802-6. PMC: 45323. DOI: 10.1073/pnas.91.25.11802. View

12.

Fuller R, Brake A, Thorner J . Intracellular targeting and structural conservation of a prohormone-processing endoprotease. Science. 1989; 246(4929):482-6. DOI: 10.1126/science.2683070. View

13.

Peery T, Steinlauf R, Koltin Y, Bruenn J . Virus-encoded toxin of Ustilago maydis: two polypeptides are essential for activity. Mol Cell Biol. 1987; 7(1):470-7. PMC: 365090. DOI: 10.1128/mcb.7.1.470-477.1987. View

14.

Holsters M, De Waele D, Depicker A, Messens E, Van Montagu M, Schell J . Transfection and transformation of Agrobacterium tumefaciens. Mol Gen Genet. 1978; 163(2):181-7. DOI: 10.1007/BF00267408. View

15.

McGurl B, Pearce G, Ryan C . Structure, expression, and antisense inhibition of the systemin precursor gene. Science. 1992; 255(5051):1570-3. DOI: 10.1126/science.1549783. View

16.

Finkler A, Peery T, Tao J, Bruenn J, Koltin I . Immunity and resistance to the KP6 toxin of Ustilago maydis. Mol Gen Genet. 1992; 233(3):395-403. DOI: 10.1007/BF00265436. View

17.

Zhu H, Bussey H, Thomas D, Gagnon J, Bell A . Determination of the carboxyl termini of the alpha and beta subunits of yeast K1 killer toxin. Requirement of a carboxypeptidase B-like activity for maturation. J Biol Chem. 1987; 262(22):10728-32. View

18.

Diamond M, Dowhanick J, Nemeroff M, Pietras D, Tu C, Bruenn J . Overlapping genes in a yeast double-stranded RNA virus. J Virol. 1989; 63(9):3983-90. PMC: 250995. DOI: 10.1128/JVI.63.9.3983-3990.1989. View

19.

Germain D, Zollinger L, Racine C, Gossard F, Dignard D, Thomas D . The yeast KEX-2-processing endoprotease is active in the Golgi apparatus of transfected NIH 3T3 fibroblasts. Mol Endocrinol. 1990; 4(10):1572-9. DOI: 10.1210/mend-4-10-1572. View

20.

Park C, Bruenn J, Ganesa C, Flurkey W, Bozarth R, Koltin Y . Structure and heterologous expression of the Ustilago maydis viral toxin KP4. Mol Microbiol. 1994; 11(1):155-64. DOI: 10.1111/j.1365-2958.1994.tb00297.x. View