Affiliation:
1. Department of Pathology and Laboratory Medicine, University of Cincinnati College of Medicine, 231 Albert Sabin Way, Cincinnati, Ohio 45267-0529
Abstract
ABSTRACT
Proper regulation of the cyclic AMP-dependent protein kinase (PKA) pathway is required for normal growth and development in many fungi. We have reported that deletion of the PKA regulatory subunit gene,
pkaR
, in
Aspergillus fumigatus
leads to defects in germination and a hypersensitivity of conidia to oxidative stress. In this study, we further analyzed the defects of Δ
pkaR
conidia and found that a large proportion were abnormally larger than wild type. Because swelling and increased susceptibility to oxidative stress are characteristic of germinating conidia, we analyzed the metabolic activity of the conidia by mitochondrial staining. Whereas it required 4 h in rich medium for wild-type mitochondria to become active, Δ
pkaR
conidia harbored active mitochondria in the absence of a germinant. Furthermore, conidia of the mutant showed a dramatic loss in viability upon short-term storage in water, indicating starvation-induced death. Taken together, our data suggest that PKA activity regulates metabolic activation of resting conidia. Additionally, the Δ
pkaR
mutant displayed an abnormal abundance of hyphal nuclei and had increased transcript levels of several cell cycle regulatory genes. These data indicate an important role for PKA in the nuclear duplication cycle of
A. fumigatus
.
Publisher
American Society for Microbiology
Subject
Molecular Biology,General Medicine,Microbiology
Cited by
12 articles.
订阅此论文施引文献
订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献