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Uptake of L-cystine via an ABC transporter contributes defense of oxidative stress in the L-cystine export-dependent manner in Escherichia coli.

Ohtsu I, Kawano Y, Suzuki M, Morigasaki S, Saiki K, Yamazaki S, Nonaka G, Takagi H - PLoS ONE (2015)

Bottom Line: Another protein YecSC is the FliY-dependent L-cystine transporter that functions cooperatively with the L-cystine transporter YdeD, which exports L-cystine as reducing equivalents from the cytoplasm to the periplasm, to prevent E. coli cells from oxidative stress.The exported L-cystine can reduce the periplasmic hydrogen peroxide to water, and then generated L-cystine is imported back into the cytoplasm via the ATP-binding cassette transporter YecSC with a high affinity to L-cystine (Km = 110 nM) in a manner dependent on FliY, the periplasmic L-cystine-binding protein.From these findings, we propose that the hydrogen peroxide-inducible L-cystine/L-cystine shuttle system plays a role of detoxification of hydrogen peroxide before lipid peroxidation occurs, and then might specific prevent damage to membrane lipids.

View Article: PubMed Central - PubMed

Affiliation: Graduate School of Biological Sciences, Nara Institute of Science and Technology, Ikoma, Nara, Japan.

ABSTRACT
Intracellular thiols like L-cystine and L-cystine play a critical role in the regulation of cellular processes. Here we show that Escherichia coli has two L-cystine transporters, the symporter YdjN and the ATP-binding cassette importer FliY-YecSC. These proteins import L-cystine, an oxidized product of L-cystine from the periplasm to the cytoplasm. The symporter YdjN, which is expected to be a new member of the L-cystine regulon, is a low affinity L-cystine transporter (Km = 1.1 μM) that is mainly involved in L-cystine uptake from outside as a nutrient. E. coli has only two L-cystine importers because ΔydjNΔyecS mutant cells are not capable of growing in the minimal medium containing L-cystine as a sole sulfur source. Another protein YecSC is the FliY-dependent L-cystine transporter that functions cooperatively with the L-cystine transporter YdeD, which exports L-cystine as reducing equivalents from the cytoplasm to the periplasm, to prevent E. coli cells from oxidative stress. The exported L-cystine can reduce the periplasmic hydrogen peroxide to water, and then generated L-cystine is imported back into the cytoplasm via the ATP-binding cassette transporter YecSC with a high affinity to L-cystine (Km = 110 nM) in a manner dependent on FliY, the periplasmic L-cystine-binding protein. The double disruption of ydeD and fliY increased cellular levels of lipid peroxides. From these findings, we propose that the hydrogen peroxide-inducible L-cystine/L-cystine shuttle system plays a role of detoxification of hydrogen peroxide before lipid peroxidation occurs, and then might specific prevent damage to membrane lipids.

No MeSH data available.


Related in: MedlinePlus

E. coli possesses two CySS importers of FliY-YecSC and YdjN.Growth of the CySS importer gene disruptants was monitored in M9 medium containing sulfate (A) or CySS (B) as a sole sulfur source.
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pone.0120619.g002: E. coli possesses two CySS importers of FliY-YecSC and YdjN.Growth of the CySS importer gene disruptants was monitored in M9 medium containing sulfate (A) or CySS (B) as a sole sulfur source.

Mentions: To evaluate the relationship between the putative CySS importers and CySS utilization in growth, the wild-type, ΔyecS, ΔydjN, and ΔydjNΔyecS mutant cells were grown in M9 medium containing 2 mM MgSO4 (Fig. 2A) or 1 mM CySS (Fig. 2B) as a sole sulfur source. All mutants were capable of growing in M9 medium containing sulfate as a sole sulfur source as well as the wild-type strain. By contrast, in the presence of CySS as a sole sulfur source, ΔyecS and ΔydjN normally grew as well as the wild-type, whereas the growth of ΔydjNΔyecS was completely abolished. These results indicate that ydjN and yecS are essential for growth utilizing CySS as a sole sulfur source, suggesting that E. coli possesses two different CySS importers, FliY-YecSC and YdjN.


Uptake of L-cystine via an ABC transporter contributes defense of oxidative stress in the L-cystine export-dependent manner in Escherichia coli.

Ohtsu I, Kawano Y, Suzuki M, Morigasaki S, Saiki K, Yamazaki S, Nonaka G, Takagi H - PLoS ONE (2015)

E. coli possesses two CySS importers of FliY-YecSC and YdjN.Growth of the CySS importer gene disruptants was monitored in M9 medium containing sulfate (A) or CySS (B) as a sole sulfur source.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4383340&req=5

pone.0120619.g002: E. coli possesses two CySS importers of FliY-YecSC and YdjN.Growth of the CySS importer gene disruptants was monitored in M9 medium containing sulfate (A) or CySS (B) as a sole sulfur source.
Mentions: To evaluate the relationship between the putative CySS importers and CySS utilization in growth, the wild-type, ΔyecS, ΔydjN, and ΔydjNΔyecS mutant cells were grown in M9 medium containing 2 mM MgSO4 (Fig. 2A) or 1 mM CySS (Fig. 2B) as a sole sulfur source. All mutants were capable of growing in M9 medium containing sulfate as a sole sulfur source as well as the wild-type strain. By contrast, in the presence of CySS as a sole sulfur source, ΔyecS and ΔydjN normally grew as well as the wild-type, whereas the growth of ΔydjNΔyecS was completely abolished. These results indicate that ydjN and yecS are essential for growth utilizing CySS as a sole sulfur source, suggesting that E. coli possesses two different CySS importers, FliY-YecSC and YdjN.

Bottom Line: Another protein YecSC is the FliY-dependent L-cystine transporter that functions cooperatively with the L-cystine transporter YdeD, which exports L-cystine as reducing equivalents from the cytoplasm to the periplasm, to prevent E. coli cells from oxidative stress.The exported L-cystine can reduce the periplasmic hydrogen peroxide to water, and then generated L-cystine is imported back into the cytoplasm via the ATP-binding cassette transporter YecSC with a high affinity to L-cystine (Km = 110 nM) in a manner dependent on FliY, the periplasmic L-cystine-binding protein.From these findings, we propose that the hydrogen peroxide-inducible L-cystine/L-cystine shuttle system plays a role of detoxification of hydrogen peroxide before lipid peroxidation occurs, and then might specific prevent damage to membrane lipids.

View Article: PubMed Central - PubMed

Affiliation: Graduate School of Biological Sciences, Nara Institute of Science and Technology, Ikoma, Nara, Japan.

ABSTRACT
Intracellular thiols like L-cystine and L-cystine play a critical role in the regulation of cellular processes. Here we show that Escherichia coli has two L-cystine transporters, the symporter YdjN and the ATP-binding cassette importer FliY-YecSC. These proteins import L-cystine, an oxidized product of L-cystine from the periplasm to the cytoplasm. The symporter YdjN, which is expected to be a new member of the L-cystine regulon, is a low affinity L-cystine transporter (Km = 1.1 μM) that is mainly involved in L-cystine uptake from outside as a nutrient. E. coli has only two L-cystine importers because ΔydjNΔyecS mutant cells are not capable of growing in the minimal medium containing L-cystine as a sole sulfur source. Another protein YecSC is the FliY-dependent L-cystine transporter that functions cooperatively with the L-cystine transporter YdeD, which exports L-cystine as reducing equivalents from the cytoplasm to the periplasm, to prevent E. coli cells from oxidative stress. The exported L-cystine can reduce the periplasmic hydrogen peroxide to water, and then generated L-cystine is imported back into the cytoplasm via the ATP-binding cassette transporter YecSC with a high affinity to L-cystine (Km = 110 nM) in a manner dependent on FliY, the periplasmic L-cystine-binding protein. The double disruption of ydeD and fliY increased cellular levels of lipid peroxides. From these findings, we propose that the hydrogen peroxide-inducible L-cystine/L-cystine shuttle system plays a role of detoxification of hydrogen peroxide before lipid peroxidation occurs, and then might specific prevent damage to membrane lipids.

No MeSH data available.


Related in: MedlinePlus