Functional analysis of the calcineurin-encoding gene cnaA from Aspergillus oryzae: evidence for its putative role in stress adaptation.
The presence of putative STRE (stress response regulatory element) and HSF (heat-shock factor) transcription factor binding sites in the promoter region of the gene encoding calcineurin ( cnaA) from Aspergillus oryzae implicated a probable role for calcineurin in the stress response. The activity of calcineurin was enhanced during growth of the wild-type strain in the presence of 1 M NaCl (2.6-fold), at alkaline pH 10.0 (2.9-fold) and at 37 degrees C (1.6-fold). The induction of cnaA antisense expression resulted in reduced calcineurin activity (1.4-fold) and caused a growth defect under the stress conditions. Induction of a strain overexpressing cnaA resulted in an increase in calcineurin activity under stress conditions, such as the presence of 1 M NaCl (73%), alkaline pH 10.0 (70%), and a temperature of 37 degrees C (50%), in addition to tolerance to FK506 (a specific inhibitor of calcineurin). While a role for calcineurin in hyphal growth is well recognized, the present study suggests that stress adaptation mechanisms in filamentous fungi involve calmodulin/calcineurin-mediated signal transduction pathways.
Juvvadi
Praveen Rao
PR
Department of Biotechnology, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-Ku 113-8657 Tokyo, Japan.
Kuroki
Yutaka
Y
Arioka
Manabu
M
Nakajima
Harushi
H
Kitamoto
Katsuhiko
K
D000222:Adaptation, Physiological; D001236:Aspergillus oryzae / Q000235:genetics / Q000378:metabolism* / Q000648:ultrastructure; D001483:Base Sequence; D019703:Calcineurin / Q000235:genetics* / Q000378:metabolism / Q000502:physiology*; D004271:DNA, Fungal / Q000032:analysis / Q000235:genetics; D015966:Gene Expression Regulation, Fungal; D005800:Genes, Fungal; D006863:Hydrogen-Ion Concentration; D008969:Molecular Sequence Data; D016415:Sequence Alignment; D012965:Sodium Chloride; D013696:Temperature
D004271:DNA, Fungal; D012965:Sodium Chloride; D019703:Calcineurin