Osmotic effects on the polyamine pathway of Neurospora crassa.
In bacteria, mammals, and certain plants, the induction of the polyamine synthetic enzyme, ornithine decarboxylase (ODC), and the accumulation of its product, putrescine, follows osmotic manipulations of cells. In at least some of these cases, this response is indispensable for survival. We wished to determine whether the polyamine pathway of Neurospora crassa was regulated in response to hyper- or hypoosmotic conditions. Unlike ODC of most other classes of organisms, the N. crassa enzyme and the accumulation of putrescine appears to be relatively indifferent to these conditions, either during sudden transitions or in steady-state. We conclude that other mechanisms of osmotic adjustment or tolerance have evolved in N. crassa and perhaps other fungi that obviate the need for putrescine accumulation.
Davis
R H
RH
Department of Molecular Biology and Biochemistry, University of California at Irvine 92717, USA.
Ristow
J L
JL
D003470:Culture Media; D007700:Kinetics; D016296:Mutagenesis; D009492:Neurospora crassa / Q000187:drug effects / Q000201:enzymology / Q000502:physiology*; D009955:Ornithine Decarboxylase / Q000378:metabolism*; D009994:Osmolar Concentration; D011073:Polyamines / Q000378:metabolism*; D011188:Potassium / Q000494:pharmacology; D011700:Putrescine / Q000378:metabolism; D013012:Sorbitol / Q000494:pharmacology; D013095:Spermidine / Q000378:metabolism
D003470:Culture Media; D011073:Polyamines; D013012:Sorbitol; D009955:Ornithine Decarboxylase; D011188:Potassium; D013095:Spermidine; D011700:Putrescine