Mechanism of nickel resistance in a cobalt-resistant wall-less mutant of Neurospora crassa (fz; sg; os-1).
A cobalt-resistant wall-less mutant of N. crassa (Cor-sl) characterized previously was also found to be 3-fold more resistant to nickel when compared to the parent wall-less mutant (W-sl). The Cor-sl strain accumulates relatively lower amounts of nickel when compared to W-sl. Sub-cellular fractionation showed significant quantities of nickel to be associated with nuclear and mitochondrial fractions in both the wall-less mutants. However significant differences were observed in vacuolar fractions of W-sl and Cor-sl strains. Fractionation of cell-free extracts on Sephadex G-10 column resolved nickel into two peaks, of which the peak II in Cor-sl constituted 70% of nickel, while the same in W-sl was about 30%. A 3-fold increase in histidine content was observed in case of Cor-sl as compared to W-sl strain, suggesting its role in Ni-resistance.
Rajyalaxmi
R Sri
RS
Department of Biochemistry, Osmania University, Hyderabad, India.
Sowjanya
T Naga
TN
Kiranmayi
P
P
Mohan
Maruthi P
MP
D002473:Cell Wall / Q000502:physiology*; D003035:Cobalt / Q000032:analysis / Q000494:pharmacology* / Q000633:toxicity*; D025141:Drug Resistance, Fungal; D006639:Histidine / Q000378:metabolism; D009154:Mutation / Q000235:genetics*; D009492:Neurospora crassa / Q000166:cytology / Q000187:drug effects* / Q000235:genetics; D009532:Nickel / Q000032:analysis / Q000633:toxicity*; D013347:Subcellular Fractions
D003035:Cobalt; D006639:Histidine; D009532:Nickel