Both gram negative and gram positive bacteria have enzymes for metabolizing alkanes. The alpha proteobacteria Caulobacter crescentus has a medium‐chain alkane hydroxylase that is a member of the ...CYP153 family of cytochrome P450 enzymes. The molecular mechanism controlling transcription of this hydroxylase has not been described. We carried out a reverse genetics screen and RNA‐seq to find the transcription factor regulating this alkane hydroxylase. A deletion of the transcription factor, named CoxR, resulted in upregulation of both the alkane hydroxylase as well as ferredoxin and ferredoxin reductase enzymes. Gel shift assays demonstrated that CoxR bound directly to the promoter of the alkane hydroxylase. In conclusion, we have identified a novel transcription factor involved in metabolism of alkanes.
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Some gram negative and gram positive bacteria have evolved enzymes for metabolizing alkanes. A medium‐chain alkane hydroxylase has been found in the model organism Caulobacter ...crescentus, belonging to the CYP153 family of cytochrome P450 enzymes. However, the molecular mechanisms regulating expression of this enzyme are still unknown. We carried out a reverse genetics screen and RNA‐seq to identify CoxR as a transcription factor regulating this alkane hydroxylase. A deletion of coxR resulted in upregulation of both the alkane hydroxylase as well as ferredoxin and ferredoxin reductase enzymes. EMSA assays showed that CoxR bound directly to a short region of the alkane hydroxylase promoter. In summary, we have identified a novel transcription factor involved in metabolism of alkanes.
Alkanes are commonly found in nature and many gram positive and gram negative bacteria have developed enzymes for degrading them. The alphaproteobacteria Caulobacter crescentus has the CYP153 gene ...which codes for a medium‐chain alkane hydroxylase in the cytochrome P450 family. However, the regulatory mechanism controlling this gene has not been well‐characterized. A reverse genetics screen found that a deletion in the TetR family coxR gene results in a strain that is sensitive to oxidative stress. We used RNA‐seq and EMSA with Ni‐NTA purified CoxR to determine which genes CoxR directly regulates. Expression of the CYP153, ferredoxin and ferredoxin reductase genes were shown to be upregulated in the coxR deletion strain. Furthermore, CoxR was shown to directly bind to a 35bp region of the CYP153 promoter. In summary, we have shown that the transcription factor CoxR directly represses CYP153 gene expression.
This is from the Experimental Biology 2019 Meeting. There is no full text article associated with this published in The FASEB Journal.
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All aerobically growing organisms have developed mechanisms for coping with oxidative stress. While the oxidative stress response has been well‐studied in some bacteria such as ...Escherichia coli, it is not as well‐characterized in other bacterial groups such as alphaproteobacteria. Here we examine the role of transcription factors in the oxidative stress response in Caulobacter crescentus. Using viability assays, we find that a deletion in the transcription factor CoxR leads to a strain that is more sensitive to hydrogen peroxide treatment but there are no obvious changes in viability in response to DNA damage agents such mitomycin C, and heat shock. Global gene expression and qRT‐PCR analysis suggested that the CoxR deletion strain has altered gene expression of NADPH cycling enzymes. In summary, CoxR is critical for the oxidative stress response.
The specialty of Laboratory Genetics and Genomics (LGG) was created in 2017 in an effort to reflect the increasing convergence in technologies and approaches between clinical molecular genetics and ...clinical cytogenetics. However, there has not yet been any formal evaluation of the merging of these disciplines and the challenges faced by Program Directors (PDs) tasked with ensuring the successful training of laboratory geneticists under the new model.
An electronic multi-question Qualtrics survey was created and was sent to the PD for each of the Accreditation Council for Graduate Medical Education–accredited LGG fellowship programs at the time. The data were collected, and the responses were aggregated for each question.
All of the responding PDs had started training at least 1 LGG fellow. PDs noted challenges with funding, staff shortages, molecular/cytogenetics content integration, limited total training time, increased remote work, increased sendout testing, and a lack of prior cytogenetics knowledge among incoming fellows.
This survey attempted to assess the challenges that LGG PDs have been facing in offering and integrating clinical molecular genetics and clinical cytogenetics fellowship training. Common challenges between programs were noted, and a set of 6 concluding comments are provided to facilitate future discussion.
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