An inhibitor-resistant histone deacetylase in the plant pathogenic fungus Cochliobolus carbonum.
We have partially purified and characterized histone deacetylases of the plant pathogenic fungus Cochliobolus carbonum. Depending on growth conditions, this fungus produces HC-toxin, a specific histone deacetylase inhibitor. Purified enzymes were analyzed by immunoblotting, by immunoprecipitation, and for toxin sensitivity. The results demonstrate the existence of at least two distinct histone deacetylase activities. A high molecular weight complex (430,000) is sensitive to HC-toxin and trichostatin A and shows immunoreactivity with an antibody against Cochliobolus HDC2, an enzyme homologous to yeast RPD3. The second activity, a 60,000 molecular weight protein, which is resistant even to high concentrations of well-known deacetylase inhibitors, such as HC-toxin and trichostatin A, is not recognized by antibodies against Cochliobolus HDC1 (homologous to yeast HOS2) or HDC2 and represents a different and/or modified histone deacetylase which is enzymatically active in its monomeric form. This enzyme activity is not present in the related filamentous fungus Aspergillus nidulans. Furthermore, in vivo treatment of Cochliobolus mycelia with trichostatin A and analysis of HDACs during the transition from non-toxin-producing to toxin-producing stages support an HC-toxin-dependent enzyme activity profile.
Brosch
G
G
Department of Microbiology, University of Innsbruck, Medical School, A-6020 Innsbruck, Austria. gerald.brosch@uibk.ac.at
Dangl
M
M
Graessle
S
S
Loidl
A
A
Trojer
P
P
Brandtner
E M
EM
Mair
K
K
Walton
J D
JD
Baidyaroy
D
D
Loidl
P
P
D001203:Ascomycota / Q000201:enzymology*; D001233:Aspergillus nidulans / Q000201:enzymology; D002467:Cell Nucleus / Q000378:metabolism; D002845:Chromatography; D004591:Electrophoresis, Polyacrylamide Gel; D004791:Enzyme Inhibitors / Q000378:metabolism / Q000494:pharmacology; D056572:Histone Deacetylase Inhibitors; D006655:Histone Deacetylases / Q000737:chemistry* / Q000378:metabolism; D006657:Histones / Q000378:metabolism; D015151:Immunoblotting; D011233:Precipitin Tests; D011485:Protein Binding; D011994:Recombinant Proteins / Q000378:metabolism; D038281:Silent Information Regulator Proteins, Saccharomyces cerevisiae; D056565:Sirtuin 2; D037761:Sirtuins; D013997:Time Factors; D015534:Trans-Activators / Q000378:metabolism
D004791:Enzyme Inhibitors; D056572:Histone Deacetylase Inhibitors; D006657:Histones; D011994:Recombinant Proteins; D038281:Silent Information Regulator Proteins, Saccharomyces cerevisiae; D015534:Trans-Activators; C087778:SIR2 protein, S cerevisiae; D056565:Sirtuin 2; D037761:Sirtuins; D006655:Histone Deacetylases