PMID- 9150225
OWN - NLM
STAT- MEDLINE
DCOM- 19970609
LR  - 20190508
IS  - 0021-9193 (Print)
IS  - 1098-5530 (Electronic)
IS  - 0021-9193 (Linking)
VI  - 179
IP  - 10
DP  - 1997 May
TI  - Two divergent catalase genes are differentially regulated during Aspergillus 
      nidulans development and oxidative stress.
PG  - 3284-92
AB  - Catalases are ubiquitous hydrogen peroxide-detoxifying enzymes that are central 
      to the cellular antioxidant response. Of two catalase activities detected in the 
      fungus Aspergillus nidulans, the catA gene encodes the spore-specific catalase A 
      (CatA). Here we characterize a second catalase gene, identified after probing a 
      genomic library with catA, and demonstrate that it encodes catalase B. This gene, 
      designated catB, predicts a 721-amino-acid polypeptide (CatB) showing 78% 
      identity to an Aspergillus fumigatus catalase and 61% identity to Aspergillus 
      niger CatR. Notably, similar levels of identity are found when comparing CatB to 
      Escherichia coli catalase HPII (43%), A. nidulans CatA (40%), and the predicted 
      peptide of a presumed catA homolog from A. fumigatus (38%). In contrast, the last 
      two peptides share a 79% identity. The catalase B activity was barely detectable 
      in asexual spores (conidia), disappeared after germination, and started to 
      accumulate 10 h after spore inoculation, throughout growth and conidiation. The 
      catB mRNA was absent from conidia, and its accumulation correlated with catalase 
      activity, suggesting that catB expression is regulated at the transcription 
      level. In contrast, the high CatA activity found in spores was lost gradually 
      during germination and growth. In addition to its developmental regulation, CatB 
      was induced by H2O2, heat shock, paraquat, or uric acid catabolism but not by 
      osmotic stress. This pattern of regulation and the protective role against H2O2 
      offered by CatA and CatB, at different stages of the A. nidulans life cycle, 
      suggest that catalase gene redundancy performs the function of satisfying 
      catalase demand at the two different stages of metabolic and genetic regulation 
      represented by growing hyphae versus spores. Alternative H2O2 detoxification 
      pathways in A. nidulans were indicated by the fact that catA/catB double mutants 
      were able to grow in substrates whose catabolism generates H2O2.
FAU - Kawasaki, L
AU  - Kawasaki L
AD  - Instituto de Fisiologia Celular, Universidad Nacional Autonoma de Mexico, D.F.
FAU - Wysong, D
AU  - Wysong D
FAU - Diamond, R
AU  - Diamond R
FAU - Aguirre, J
AU  - Aguirre J
LA  - eng
SI  - GENBANK/U80672
GR  - AI 15338/AI/NIAID NIH HHS/United States
GR  - DK 51478/DK/NIDDK NIH HHS/United States
PT  - Comparative Study
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PT  - Research Support, U.S. Gov't, P.H.S.
PL  - United States
TA  - J Bacteriol
JT  - Journal of bacteriology
JID - 2985120R
RN  - BBX060AN9V (Hydrogen Peroxide)
RN  - EC 1.11.1.6 (Catalase)
SB  - IM
MH  - Amino Acid Sequence
MH  - Aspergillus nidulans/*enzymology/*genetics/growth & development
MH  - Base Sequence
MH  - Biotransformation/genetics
MH  - Catalase/*genetics/metabolism/physiology
MH  - Cloning, Molecular
MH  - Enzyme Activation/genetics
MH  - Gene Expression Regulation, Fungal/*physiology
MH  - Genes, Fungal/*physiology
MH  - Hydrogen Peroxide/metabolism
MH  - Molecular Sequence Data
MH  - *Oxidative Stress
PMC - PMC179108
EDAT- 1997/05/01 00:00
MHDA- 1997/05/01 00:01
PMCR- 1997/05/01
CRDT- 1997/05/01 00:00
PHST- 1997/05/01 00:00 [pubmed]
PHST- 1997/05/01 00:01 [medline]
PHST- 1997/05/01 00:00 [entrez]
PHST- 1997/05/01 00:00 [pmc-release]
AID - 10.1128/jb.179.10.3284-3292.1997 [doi]
PST - ppublish
SO  - J Bacteriol. 1997 May;179(10):3284-92. doi: 10.1128/jb.179.10.3284-3292.1997.