Characterization of NikA histidine kinase and two response regulators with special reference to osmotic adaptation and asexual development in Aspergillus nidulans.
Aspergillus nidulans has many histidine-to-aspartate (His-Asp) phosphorelay components, including 15 histidine kinases (HKs), four response regulators (RRs), and a histidine-containing phosphotransfer intermediate (HPt). Of these, NikA (HK) is highly conserved in many filamentous fungi. It has been found that NikA is responsible for the responses of filamentous fungi to fungicides such as iprodione and fludioxonil. Two RRs, SskA and SrrA, are also involved in the fungicide response, providing a typical example of the His-Asp phosphorelay system, in which NikA functions as a sensor upstream of SskA and SrrA in response to fungicides. To gain further insight into the physiological roles of the NikA-SskA/SrrA phosphorelay system, we constructed a pair of DeltanikADeltasskA and DeltanikADeltasrrA double mutants. Here we provide evidence regarding the crucial involvement of the NikA-SskA/SrrA phosphorelay system in both osmotic adaptation and asexual development, including conidia formation. Based on these results, a general insight into the A. nidulans His-Asp phosphorelay network is also discussed.
Hagiwara
Daisuke
D
New Industry Creation Hatchery Center, Tohoku University, Aramaki, Sendai, Japan. dhaggy@niche.tohoku.ac.jp
Mizuno
Takeshi
T
Abe
Keietsu
K
D000222:Adaptation, Physiological; D001233:Aspergillus nidulans / Q000187:drug effects / Q000201:enzymology* / Q000378:metabolism / Q000502:physiology*; D025141:Drug Resistance, Fungal; D005659:Fungicides, Industrial / Q000494:pharmacology; D000071677:Histidine Kinase; D009995:Osmosis; D011494:Protein Kinases / Q000235:genetics / Q000378:metabolism*; D012100:Reproduction, Asexual; D017384:Sequence Deletion; D015398:Signal Transduction; D013172:Spores, Fungal / Q000201:enzymology
D005659:Fungicides, Industrial; D011494:Protein Kinases; D000071677:Histidine Kinase