scholarly journals Histone Hyperacetylation in Maize in Response to Treatment with HC-Toxin or Infection by the Filamentous Fungus Cochliobolus carbonum

1997 ◽  
Vol 115 (3) ◽  
pp. 1021-1027 ◽  
Author(s):  
R. F. Ransom ◽  
J. D. Walton
Keyword(s):  
Filamentous Fungus ◽  
Response To Treatment ◽  
Cochliobolus Carbonum ◽  
Histone Hyperacetylation ◽  
Hc Toxin

scholarly journals A Fatty Acid Synthase Gene in Cochliobolus carbonum Required for Production of HC-Toxin, Cyclo(d-Prolyl-l-Alanyl- d-Alanyl- l-2-Amino-9,10-Epoxi-8-Oxodecanoyl)

1997 ◽  
Vol 10 (2) ◽  
pp. 207-214 ◽  
Author(s):  
Joong-Hoon Ahn ◽  
Jonathan D. Walton
Keyword(s):  
Fatty Acid ◽  
Fatty Acid Synthase ◽  
Cyclic Peptide ◽  
Decanoic Acid ◽  
Toxin Production ◽  
Gene Encoding ◽  
Cochliobolus Carbonum ◽  
Primary Amino ◽  
Hc Toxin

The fungal maize pathogen Cochliobolus carbonum produces a phytotoxic and cytostatic cyclic peptide, HC-toxin, of structure cyclo(D-prolyl-L-alanyl-D-alanyl-L-Aeo), in which Aeo stands for 2-amino-9,10-epoxi-8-oxodecanoic acid. Here we report the isolation of a gene, TOXC, that is present only in HC-toxin-producing (Tox2+) fungal strains. TOXC is present in most Tox2+ strains in three functional copies, all of which are on the same chromosome as the gene encoding HC-toxin synthetase. When all copies of TOXC are mutated by targeted gene disruption, the fungus grows and sporulates normally in vitro but no longer makes HC-toxin and is not pathogenic, indicating that TOXC has a specific role in HC-toxin production and hence virulence. The TOXC mRNA is 6.5 kb and the predicted product has 2,080 amino acids and a molecular weight of 233,000. The primary amino acid sequence is highly similar (45 to 47% identity) to the β subunit of fatty acid synthase from several lower eukaryotes, and contains, in the same order as in other β subunits, domains predicted to encode acetyl transferase, enoyl reductase, dehydratase, and malonyl-palmityl transferase. The most plausible function of TOXC is to contribute to the synthesis of the decanoic acid backbone of Aeo.

scholarly journals Cloning and Mapping of a Putative Barley NADPH-Dependent HC-Toxin Reductase

1997 ◽  
Vol 10 (2) ◽  
pp. 234-239 ◽  
Author(s):  
F. Han ◽  
A. Kleinhofs ◽  
A. Kilian ◽  
S. E. Ullrich
Keyword(s):  
Plant Species ◽  
Chromosome 9 ◽  
Immature Embryos ◽  
Chromosome 1 ◽  
Grass Species ◽  
Cochliobolus Carbonum ◽  
Wide Range ◽  
Young Leaves ◽  
High Conservation ◽  
Hc Toxin

The NADPH-dependent HC-toxin reductase (HCTR), encoded by Hm1 in maize, inactivates HC-toxin produced by the fungus Cochliobolus carbonum, and thus confers resistance to the pathogen. The fact that C. carbonum only infects maize (Zea mays) and is the only species known to produce HC-toxin raises the question: What are the biological functions of HCTR in other plant species? An HCTR-like enzyme may function to detoxify toxins produced by pathogens which infect other plant species (R. B. Meeley, G. S. Johal, S. E. Briggs, and J. D. Walton, Plant Cell, 4:71–77, 1992). Hm1 homolog in rice (Y. Hihara, M. Umeda, C. Hara, Q. Liu, S. Aotsuka, K. Toriyama, and H. Uchimiya, unpublished) and HCTR activity in barley, wheat, oats and sorghum have been reported (R. B. Meeley and J. D. Walton, Plant Physiol. 97:1080–1086, 1993). To investigate the sequence conservation of Hm1 and HCTR in barley and the possible relationship of barley Hm1 homolog to the known disease resistance genes, we cloned and mapped a barley (Hordeum vulgare) Hm1-like gene. A putative full-length cDNA clone, Bhm1-18, was isolated from a cDNA library consisting of mRNA from young leaves, inflorescences, and immature embryos. This 1,297-bp clone encodes 363 amino acids which show great similarity (81.6%) with the amino acid sequence of HM1 in maize. Two loci were mapped to barley molecular marker linkage maps with Bhm1-18 as the probe; locus A (Bhm1A) on the long arm of chromosome 1, and locus B (Bhm1B) on the short arm of chromosome 1 which is syntenic to maize chromosome 9 containing the Hm2 locus. The Bhm1-18 probe hybridized strongly to a Southern blot of a wide range of grass species, indicating high conservation of HCTR at the DNA sequence level among grasses. The HCTR mRNA was detected in barley roots, leaves, inflorescences, and immature embryos. The conservation of the HCTR sequence, together with its expression in other plant species (R. B. Meeley and J. D. Walton, Plant Physiol. 97:1080–1086, 1993), suggests HCTR plays an important functional role in other plant species.

scholarly journals An Extended Physical Map of the TOX2 Locus of Cochliobolus carbonum Required for Biosynthesis of HC-Toxin

2002 ◽  
Vol 35 (1) ◽  
pp. 31-38 ◽  
Author(s):  
Joong-Hoon Ahn ◽  
Yi-Qiang Cheng ◽  
Jonathan D. Walton
Keyword(s):  
Physical Map ◽  
Cochliobolus Carbonum ◽  
Hc Toxin

scholarly journals Inhibition of maize histone deacetylases by HC toxin, the host-selective toxin of Cochliobolus carbonum.

1995 ◽  
Vol 7 (11) ◽  
pp. 1941-1950 ◽  
Author(s):  
G Brosch ◽  
R Ransom ◽  
T Lechner ◽  
J D Walton ◽  
P Loidl
Keyword(s):  
Histone Deacetylases ◽  
Cochliobolus Carbonum ◽  
Hc Toxin

scholarly journals Histone Deacetylase Activity and Phytotoxic Effects Following Exposure of Duckweed (Lemna pausicostata L.) to Apicidin and HC-Toxin

2001 ◽  
Vol 91 (12) ◽  
pp. 1141-1148 ◽  
Author(s):  
Hamed K. Abbas ◽  
John W. Gronwald ◽  
Kathryn L. Plaisance ◽  
Rex N. Paul ◽  
Yin W. Lee
Keyword(s):  
Cell Division ◽  
Histone Deacetylase ◽  
Chlorophyll Synthesis ◽  
Effective Concentration ◽  
Starch Accumulation ◽  
Fusarium Spp ◽  
Cochliobolus Carbonum ◽  
Hc Toxin ◽  
Cyclic Tetrapeptide

The effects of two cyclic tetrapeptide fungal toxins, apicidin (from Fusarium spp.) and HC-toxin (from Cochliobolus carbonum), on duckweed (Lemna pausicostata L.) were examined. Both toxins inhibited histone deacetylase (HD) activity from duckweed plantlets; the effective concentration (EC50) for inhibition of HD was 5.6 and 1.1 μM for apicidin and HC-toxin, respectively. Approximately 65 and 85% of in vitro HD activity was inhibited by 50 μM apicidin or HC-toxin, respectively. Exposing duckweed for 72 h to apicidin or HC-toxin (25 or 50 μM) enhanced cellular leakage, impaired chlorophyll synthesis, and inhibited growth (cell division). At equivalent concentrations, the effects of HC-toxin were more pronounced than those of apicidin. In fronds, 72 h of exposure to 50 μM apicidin resulted in chloroplast deterioration indicated by loss of orientation and excess starch accumulation. In roots, a 72-h treatment with 50 μM apicidin resulted in the loss of the root cap and increased vacuolization and starch accumulation in plastids.

scholarly journals Fungal Induced Protein Hyperacetylation Identified by Acetylome Profiling

2016 ◽  
Author(s):  
Justin W Walley ◽  
Zhouxin Shen ◽  
Maxwell R. McReynolds ◽  
Steven P. Briggs
Keyword(s):  
Immune Response ◽  
Protein Function ◽  
Effector Proteins ◽  
Protein Acetylation ◽  
Post Translational Modification ◽  
Cochliobolus Carbonum ◽  
Pathogen Virulence ◽  
Pathogen Effector ◽  
Race 1 ◽  
Hc Toxin

ABSTRACTLysine acetylation is a key post-translational modification that regulates diverse proteins involved in a range of biological processes. The role of histone acetylation in plant defense is well established and it is known that pathogen effector proteins encoding acetyltransferses can directly acetylate host proteins to alter immunity. However, it is unclear whether endogenous plant enzymes can modulate protein acetylation during an immune response. Here we investigate how the effector molecule HC-toxin, a histone deacetylase inhibitor, produced by Cochliobolus carbonum race 1 promotes pathogen virulence in maize through altering protein acetylation. Using mass spectrometry we globally quantified the abundance of 3,636 proteins and the levels of acetylation at 2,791 sites in maize plants treated with HC-toxin as well as HC-toxin deficient or producing strains of C. carbonum. Analyses of these data demonstrate that acetylation is a widespread post-translational modification impacting proteins encoded by many intensively studied maize genes. Furthermore, the application of exogenous HC-toxin enabled us to show that the activity of plant-encoded enzymes can be modulated to alter acetylation of non-histone proteins during an immune response. Collectively, these results provide a resource for further mechanistic studies examining the regulation of protein function and offer insight into the complex immune response triggered by virulent C. carbonum.

scholarly journals Sodium butyrate induces histone hyperacetylation and differentiation of murine embryonal carcinoma cells.

1984 ◽  
Vol 98 (2) ◽  
pp. 602-608 ◽  
Author(s):  
P A McCue ◽  
M L Gubler ◽  
M I Sherman ◽  
B N Cohen
Keyword(s):  
Sodium Butyrate ◽  
Embryonal Carcinoma ◽  
Carcinoma Cells ◽  
The Other ◽  
Response To Treatment ◽  
Embryonal Carcinoma Cells ◽  
Histone Hyperacetylation ◽  
Butyrate Treatment ◽  
Ec Cells ◽  
Modest Level

Cells from embryonal carcinoma (EC) lines 6050AJ and PCC4.aza 1R differentiate in response to treatment with sodium butyrate as well as retinoic acid (RA) or hexamethylenebisacetamide (HMBA). Murine 6050AJ EC cells exposed to sodium butyrate possess hyperacetylated forms of histones H4 and altered forms of histones H2a and H2b, whereas histones from cells treated with other inducers appear to be unaffected. These results might indicate that the mechanism by which sodium butyrate promotes differentiation of EC cells is different from the ways in which RA and HMBA act. Differentiation-defective PCC4(RA)-1 EC cells fail to respond to RA, presumably because they possess minimal amounts of active binding protein for RA (cRABP). Sodium butyrate treatment of these cells results in only a modest level of differentiation. On the other hand, exposure to sodium butyrate plus RA leads to extensive differentiation. As is the case with 6050AJ cells, PCC4(RA)-1 cells treated with sodium butyrate also contain hyperacetylated histones. Furthermore, these cells now possess high levels of cRABP. The latter observations suggest that sodium butyrate has the ability to reactivate a silent cRABP gene in PCC4(RA)-1 cells and thereby lead to extensive differentiation via the retinoid pathway when RA is added.

Inhibition of Maize Histone Deacetylases by HC Toxin, the Host-Selective Toxin of Cochliobolus carbonum

1995 ◽  
Vol 7 (11) ◽  
pp. 1941 ◽  
Author(s):  
Gerald Brosch ◽  
Richard Ransom ◽  
Thomas Lechner ◽  
Jonathan D. Walton ◽  
Peter Loidl
Keyword(s):  
Histone Deacetylases ◽  
Cochliobolus Carbonum ◽  
Hc Toxin
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