NAD(P)H quinone oxidoreductases (NQOs) comprise a diverse and adaptable enzyme family in both prokaryotic and eukaryotic organisms. These NAD(P)H-dependent flavoenzymes, which are able to mediate the reduction of both quinone and azo substrates, play an important role in the metabolism of quinone, azo and nitroaromatic xenobiotics by the gut microflora and in host tissues. They share a common structure comprising a characteristic homodimeric short-flavodoxin fold. Interestingly, however, there is only very low primary sequence homology (less than 10%) between human NQOs and prokaryotic azoreductases. It appears, therefore, that this superfamily formed by convergent evolution towards a common function rather than divergent evolution from a common ancestor.
As increasing numbers of azoreductases and NQOs are identified, it is becoming ever clearer that this superfamily is much larger and more diverse than originally thought. The goals of this research topic, therefore, are to capture the current state of play and highlight upcoming challenges and opportunities for further research in order to provide encouragement to investigators who are already active in the field and attract others to join this growing research community.
The NQO superfamily is clearly much larger and more diverse than originally thought. We would be happy to receive contributions relating, but not limited to the following:
• We invite contributions describing novel members of the superfamily, particularly from species in which no members of this superfamily have yet been characterized, and analysis of the pathways by which this diverse superfamily has evolved.
NQOs play a key role in the metabolic activation of prodrugs, and there is also evidence of NQO2 as a secondary target for many drugs, e.g. imatinib.
• We invite contributions describing the roles of NQOs in activating prodrugs and/or mediating drug responses.
Quinone and nitroaromatic drugs are toxicologically problematic because of their tendency to undergo redox cycling, which can involve NQOs and azoreductases.
• We invite contributions describing approaches to mitigate the cytotoxic effects of these drugs and/or methods for identifying patients at risk by means of genotyping or phenotyping.
NQOs play a variety of roles in the cell which are not directly related to their enzymatic function e.g. regulating proteasomal degradation.
• We invite contributions describing novel functions of these enzymes within the cell or expanding our understanding of existing functions.
Bacterial azoreductases in particular have great potential in the bioremediation of contaminated sites, especially following the accidental or deliberate release of industrial chemicals such as azo dyes.
• We invite contributions illustrating the practical applications of azoreductases.
Original research papers, short communications, reviews and commentaries are all welcome.
This issue will be of widespread interest within the pharmacology community as human NQOs and bacterial azoreductases are extensively studied for the activation of prodrugs. There will also be interest amongst toxicologists due to the role of bacterial azoreductases in breaking down controversial food
NAD(P)H quinone oxidoreductases (NQOs) comprise a diverse and adaptable enzyme family in both prokaryotic and eukaryotic organisms. These NAD(P)H-dependent flavoenzymes, which are able to mediate the reduction of both quinone and azo substrates, play an important role in the metabolism of quinone, azo and nitroaromatic xenobiotics by the gut microflora and in host tissues. They share a common structure comprising a characteristic homodimeric short-flavodoxin fold. Interestingly, however, there is only very low primary sequence homology (less than 10%) between human NQOs and prokaryotic azoreductases. It appears, therefore, that this superfamily formed by convergent evolution towards a common function rather than divergent evolution from a common ancestor.
As increasing numbers of azoreductases and NQOs are identified, it is becoming ever clearer that this superfamily is much larger and more diverse than originally thought. The goals of this research topic, therefore, are to capture the current state of play and highlight upcoming challenges and opportunities for further research in order to provide encouragement to investigators who are already active in the field and attract others to join this growing research community.
The NQO superfamily is clearly much larger and more diverse than originally thought. We would be happy to receive contributions relating, but not limited to the following:
• We invite contributions describing novel members of the superfamily, particularly from species in which no members of this superfamily have yet been characterized, and analysis of the pathways by which this diverse superfamily has evolved.
NQOs play a key role in the metabolic activation of prodrugs, and there is also evidence of NQO2 as a secondary target for many drugs, e.g. imatinib.
• We invite contributions describing the roles of NQOs in activating prodrugs and/or mediating drug responses.
Quinone and nitroaromatic drugs are toxicologically problematic because of their tendency to undergo redox cycling, which can involve NQOs and azoreductases.
• We invite contributions describing approaches to mitigate the cytotoxic effects of these drugs and/or methods for identifying patients at risk by means of genotyping or phenotyping.
NQOs play a variety of roles in the cell which are not directly related to their enzymatic function e.g. regulating proteasomal degradation.
• We invite contributions describing novel functions of these enzymes within the cell or expanding our understanding of existing functions.
Bacterial azoreductases in particular have great potential in the bioremediation of contaminated sites, especially following the accidental or deliberate release of industrial chemicals such as azo dyes.
• We invite contributions illustrating the practical applications of azoreductases.
Original research papers, short communications, reviews and commentaries are all welcome.
This issue will be of widespread interest within the pharmacology community as human NQOs and bacterial azoreductases are extensively studied for the activation of prodrugs. There will also be interest amongst toxicologists due to the role of bacterial azoreductases in breaking down controversial food
