Premium
An unusual MAP kinase is required for efficient penetration of the plant surface by Ustilago maydis
Author(s) -
Brachmann Andreas,
Schirawski Jan,
Müller Philip,
Kahmann Regine
Publication year - 2003
Publication title -
the embo journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 7.484
H-Index - 392
eISSN - 1460-2075
pISSN - 0261-4189
DOI - 10.1093/emboj/cdg198
Subject(s) - ustilago , biology , penetration (warfare) , microbiology and biotechnology , anatomy , genetics , botany , gene , operations research , engineering
In Ustilago maydis , pathogenic development is controlled by a heterodimer of the two homeodomain proteins bW and bE. We have identified by RNA fingerprinting a b‐regulated gene, kpp6 , which encodes an unusual MAP kinase. Kpp6 is similar to a number of other fungal MAP kinases involved in mating and pathogenicity, but contains an additional N‐terminal domain unrelated to other proteins. Transcription of the kpp6 gene yields two transcripts differing in length, but encoding proteins of identical mass. One transcript is upregulated by the bW/bE heterodimer, while the other is induced after pheromone stimulation. kpp6 deletion mutants are attenuated in pathogenicity. kpp6 T355A,Y357F mutants carrying a non‐activatable allele of kpp6 are more severely compromised in pathogenesis. These strains can still form appressoria, but are defective in the subsequent penetration of the plant cuticle. Kpp6 is expressed during all stages of the sexual life cycle except mature spores. We speculate that Kpp6 may respond to a plant signal and regulate the genes necessary for efficient penetration of plant tissue.