Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Pivot Concepts:
Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Target Concepts:
Gene/Protein
Disease
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Enzyme
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Query: UNIPROT:P04040 (
Catalase
)
3,577
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
Catalase
-3 (CAT-3) constitutes the main catalase activity in growing hyphae of Neurospora crassa, and its activity increases during exponential growth or is induced under different stress conditions. Although extensive progress has been made to identify catalase regulators, the regulation mechanism of CAT-3 at the chromatin level still remains unclear. Here, we aim at investigating the molecular regulation mechanisms of cat-3 at the chromatin level. We found that CAT-3 protein levels increased in mutants defective in proper global heterochromatin formation. Bioinformatics analysis identified a 5-kb AT-rich sequence adjacent to the cat-3 promoter as a heterochromatin region because of its enrichment of H3K9me3 and HP1. Expression of CAT-3 was induced by H
2
O
2
treatment in wild-type and such change occurred along with the accumulation of
histone H3
acetylation at 5-kb heterochromatin boundaries and cat-3 locus, but without alteration of its H3K9me3 repressive modification. Moreover, disruption of 5-kb heterochromatin region results in elevated cat-3 expression, and higher levels of cat-3 expression were promoted by the combination with global heterochromatin defective mutants. Interestingly, the molecular weight and activity bands of CAT-3 protein are different in heterochromatin defective mutants compared with those in wild-type, suggesting that its N-terminal processing and modification may be altered. Our study indicates that the local chromatin structure creates a heterochromatin repressive environment to repress nearby gene expression.
...
PMID:Regulation of Neurospora Catalase-3 by global heterochromatin formation and its proximal heterochromatin region. 2745 22
Catalase
is an important enzyme found in nearly all aerobic organisms and plays an essential role in protecting cells from oxidative damage by catalyzing the degradation of hydrogen peroxide into water and oxygen. In filamentous fungus Neurospora crassa, the expression levels of catalases are rigorously regulated by morphogenetic transition during growth and development in cells. Our study revealed that catalase-3 transcription is positively regulated by histone acetyltransferase GCN5 and the cross-pathway control gene cpc-1, as the cat-3 expression level is significantly decreased in gcn5
KO
and cpc-1 (j-5) mutants. Moreover, gcn5
KO
and cpc-1 (j-5) mutants could not respond to H
2
O
2
treatment due to the inadequate cat-3 transcription, while wild-type strains showed high expression levels of catalase upon H
2
O
2
treatment. The global H3 acetylation and the acetylation of H3 at cat-3 locus dramatically decreased in gcn5
KO
under normal or oxidative stress conditions. Meanwhile, the expression of CAT-3 is reduced in gcn5
E146Q
, the catalytically dead mutant, suggesting that the catalytic activity of GCN5 functions in regulation of cat-3 transcription. In addition, GCN5 cannot acetylate
histone H3
efficiently at cat-3 locus in cpc-1 (j-5) mutant strains under normal or oxidative stress conditions. Furthermore, ChIP assays data revealed that the CPC1/GCN4 can directly target the cat-3 promoter region, which may recruit GCN5 to modify the histone acetylation of this region. These results disclosed a distinctive function of CPC1/GCN4 in the regulatory pathway of cat-3 transcription, which is mediated by GCN5-dependent acetylation.
...
PMID:Cross-pathway control gene CPC1/GCN4 coordinates with histone acetyltransferase GCN5 to regulate catalase-3 expression under oxidative stress in Neurospora crassa. 2942 11
