In:
Eukaryotic Cell, American Society for Microbiology, Vol. 9, No. 11 ( 2010-11), p. 1711-1723
Abstract:
The opportunistic human pathogen Aspergillus fumigatus reproduces asexually by forming a massive number of mitospores called conidia. In this study, we characterize the upstream developmental regulator A. fumigatus flbB ( AfuflbB ). Northern blotting and cDNA analyses reveal that AfuflbB produces two transcripts predicted to encode two basic leucine zipper domain (bZIP) polypeptides, Afu FlbBβ (420 amino acids [aa]) and Afu FlbBα (390 aa). The deletion of AfuflbB results in delayed/reduced sporulation, precocious cell death, the lack of conidiophore development in liquid submerged culture, altered expression of AfubrlA and AfuabaA , and blocked production of gliotoxin. While introduction of the wild-type (WT) AfuflbB allele fully complemented these defects, disruption of the ATG start codon for either one of the Afu FlbB polypeptides leads to a partial complementation, indicating the need of both polypeptides for WT levels of asexual development and gliotoxin biogenesis. Consistent with this, Aspergillus nidulans flbB + encoding one polypeptide (426 aa) partially complements the AfuflbB null mutation. The presence of 0.6 M KCl in liquid submerged culture suppresses the defects caused by the lack of one, but not both, of the Afu FlbB polypeptides, suggesting a genetic prerequisite for Afu FlbB in A. fumigatus development. Finally, Northern blot analyses reveal that both AfuflbB and AfuflbE are necessary for expression of AfuflbD , suggesting that FlbD functions downstream of FlbB/FlbE in aspergilli.
Type of Medium:
Online Resource
ISSN:
1535-9778
,
1535-9786
Language:
English
Publisher:
American Society for Microbiology
Publication Date:
2010
detail.hit.zdb_id:
2071564-X
SSG:
12
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