TY - JOUR
T1 - Oxygen sensing in yeast
T2 - Evidence for the involvement of the respiratory chain in regulating the transcription of a subset of hypoxic genes
AU - Kwast, Kurt E.
AU - Burke, Patricia V.
AU - Staahl, Brett T.
AU - Poyton, Robert O.
PY - 1999/5/11
Y1 - 1999/5/11
N2 - Oxygen availability affects the transcription of a number of genes in nearly all organisms. Although the molecular mechanisms for sensing oxygen are not precisely known, heme is thought to play a pivotal role. Here we address the possibility that oxygen sensing in yeast, as in mammals, involves a redox-sensitive hemoprotein. We have found that carbon monoxide (CO) completely blocks the anoxia-induced expression of two hypoxic genes, OLE1 and CYC7, partially blocks the induction of a third gene, COX5b, and has no effect on the expression of other hypoxic or aerobic genes. In addition, transition metals (Co and Ni) induce the expression of OLE1 and CYC7 in a concentration-dependent manner under aerobic conditions. These findings suggest that the redox state of an oxygen-binding hemoprotein is involved in controlling the expression of at least two hypoxic yeast genes. By using mutants deficient in each of the two major yeast CO-binding hemoproteins (cytochrome c oxidase and flavohemoglobin), respiratory inhibitors, and cob1 and ρ0 mutants, we have found that the respiratory chain is involved in the anoxic induction of these two genes and that cytochrome c oxidase is likely the hemoprotein 'sensor.' Our findings also indicate that there are at least two classes of hypoxic genes in yeast (CO sensitive and CO insensitive) and imply that multiple pathways/mechanisms are involved in modulating the expression of hypoxic yeast genes.
AB - Oxygen availability affects the transcription of a number of genes in nearly all organisms. Although the molecular mechanisms for sensing oxygen are not precisely known, heme is thought to play a pivotal role. Here we address the possibility that oxygen sensing in yeast, as in mammals, involves a redox-sensitive hemoprotein. We have found that carbon monoxide (CO) completely blocks the anoxia-induced expression of two hypoxic genes, OLE1 and CYC7, partially blocks the induction of a third gene, COX5b, and has no effect on the expression of other hypoxic or aerobic genes. In addition, transition metals (Co and Ni) induce the expression of OLE1 and CYC7 in a concentration-dependent manner under aerobic conditions. These findings suggest that the redox state of an oxygen-binding hemoprotein is involved in controlling the expression of at least two hypoxic yeast genes. By using mutants deficient in each of the two major yeast CO-binding hemoproteins (cytochrome c oxidase and flavohemoglobin), respiratory inhibitors, and cob1 and ρ0 mutants, we have found that the respiratory chain is involved in the anoxic induction of these two genes and that cytochrome c oxidase is likely the hemoprotein 'sensor.' Our findings also indicate that there are at least two classes of hypoxic genes in yeast (CO sensitive and CO insensitive) and imply that multiple pathways/mechanisms are involved in modulating the expression of hypoxic yeast genes.
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U2 - 10.1073/pnas.96.10.5446
DO - 10.1073/pnas.96.10.5446
M3 - Article
C2 - 10318903
AN - SCOPUS:0033545977
VL - 96
SP - 5446
EP - 5451
JO - Proceedings of the National Academy of Sciences of the United States of America
JF - Proceedings of the National Academy of Sciences of the United States of America
SN - 0027-8424
IS - 10
ER -