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Cell Lysis in S. pombe ura4 Mutants Is Suppressed by Loss of Functional Pub1, Which Regulates the Uracil Transporter Fur4.

Nishino K, Kushima M, Matsuo Y, Matsuo Y, Kawamukai M - PLoS ONE (2015)

Bottom Line: Fur4 was necessary for the utilization of extracellular uracil, cytosine, or UMP.Uracil uptake activity increased in the Δpub1 strain in a Fur4-dependent manner.In summary, the increased uracil uptake ability of Δpub1 cells, where Fur4 was predominantly localized to the plasma membrane, resulted in suppression of cell lysis in the Δura4 background.

View Article: PubMed Central - PubMed

Affiliation: Department of Life Science and Biotechnology, Faculty of Life and Environmental Science, Shimane University, Matsue, Japan.

ABSTRACT
Schizosaccharomyces pombe Δura4 cells lyse when grown on YPD medium. A S. pombe non-essential gene deletion library was screened to determine suppressors of the lysis phenotype. Deletion of the pub1 gene, which encoded E3 ubiquitin ligase, strongly suppressed cell lysis in Δura4 cells. The Δpub1 cells displayed high sensitivity to 5-fluorouracil, a toxic analog of uracil, and this sensitivity was suppressed by deletion of fur4, which encoded a uracil transporter. Fur4 localized primarily to the Golgi apparatus and vacuoles in wild-type cells, but localization was predominantly at the plasma membrane in Δpub1 cells. Fur4 was necessary for the utilization of extracellular uracil, cytosine, or UMP. Uracil uptake activity increased in the Δpub1 strain in a Fur4-dependent manner. In addition, uracil starvation was critical for induction of cell lysis of Δura4 strains and uracil supplementation suppressed lysis. In summary, the increased uracil uptake ability of Δpub1 cells, where Fur4 was predominantly localized to the plasma membrane, resulted in suppression of cell lysis in the Δura4 background.

No MeSH data available.


Related in: MedlinePlus

Proposed model for interaction of Pub1 and Fur4.The uracil transporter Fur4 localizes to Golgi or vacuoles under normal growth conditions and shifts to the plasma membrane when nitrogen is consumed. Fur4 is also localized to the plasma membrane when the pub1 gene is deleted. Increased uracil uptake in pub1 mutants by the accumulated Fur4 localization in the membrane rescues the cell lysis phenotype. Ubiquitination of Fur4 is observed, but the mechanisms underlying Pub1 regulation of Fur4 localization remains to be determined. PM, Plasma Membrane.
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pone.0141796.g009: Proposed model for interaction of Pub1 and Fur4.The uracil transporter Fur4 localizes to Golgi or vacuoles under normal growth conditions and shifts to the plasma membrane when nitrogen is consumed. Fur4 is also localized to the plasma membrane when the pub1 gene is deleted. Increased uracil uptake in pub1 mutants by the accumulated Fur4 localization in the membrane rescues the cell lysis phenotype. Ubiquitination of Fur4 is observed, but the mechanisms underlying Pub1 regulation of Fur4 localization remains to be determined. PM, Plasma Membrane.

Mentions: A diagram outlying the proposed interactions of Fur4 and Pub1 is given in Fig 9. This cartoon is supported by our experimental observations, but at least two major questions relating to this mechanism remain. First, why does supplementation with uracil suppress cell lysis, and second, how does Pub1 affect Fur4 localization?


Cell Lysis in S. pombe ura4 Mutants Is Suppressed by Loss of Functional Pub1, Which Regulates the Uracil Transporter Fur4.

Nishino K, Kushima M, Matsuo Y, Matsuo Y, Kawamukai M - PLoS ONE (2015)

Proposed model for interaction of Pub1 and Fur4.The uracil transporter Fur4 localizes to Golgi or vacuoles under normal growth conditions and shifts to the plasma membrane when nitrogen is consumed. Fur4 is also localized to the plasma membrane when the pub1 gene is deleted. Increased uracil uptake in pub1 mutants by the accumulated Fur4 localization in the membrane rescues the cell lysis phenotype. Ubiquitination of Fur4 is observed, but the mechanisms underlying Pub1 regulation of Fur4 localization remains to be determined. PM, Plasma Membrane.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4633276&req=5

pone.0141796.g009: Proposed model for interaction of Pub1 and Fur4.The uracil transporter Fur4 localizes to Golgi or vacuoles under normal growth conditions and shifts to the plasma membrane when nitrogen is consumed. Fur4 is also localized to the plasma membrane when the pub1 gene is deleted. Increased uracil uptake in pub1 mutants by the accumulated Fur4 localization in the membrane rescues the cell lysis phenotype. Ubiquitination of Fur4 is observed, but the mechanisms underlying Pub1 regulation of Fur4 localization remains to be determined. PM, Plasma Membrane.
Mentions: A diagram outlying the proposed interactions of Fur4 and Pub1 is given in Fig 9. This cartoon is supported by our experimental observations, but at least two major questions relating to this mechanism remain. First, why does supplementation with uracil suppress cell lysis, and second, how does Pub1 affect Fur4 localization?

Bottom Line: Fur4 was necessary for the utilization of extracellular uracil, cytosine, or UMP.Uracil uptake activity increased in the Δpub1 strain in a Fur4-dependent manner.In summary, the increased uracil uptake ability of Δpub1 cells, where Fur4 was predominantly localized to the plasma membrane, resulted in suppression of cell lysis in the Δura4 background.

View Article: PubMed Central - PubMed

Affiliation: Department of Life Science and Biotechnology, Faculty of Life and Environmental Science, Shimane University, Matsue, Japan.

ABSTRACT
Schizosaccharomyces pombe Δura4 cells lyse when grown on YPD medium. A S. pombe non-essential gene deletion library was screened to determine suppressors of the lysis phenotype. Deletion of the pub1 gene, which encoded E3 ubiquitin ligase, strongly suppressed cell lysis in Δura4 cells. The Δpub1 cells displayed high sensitivity to 5-fluorouracil, a toxic analog of uracil, and this sensitivity was suppressed by deletion of fur4, which encoded a uracil transporter. Fur4 localized primarily to the Golgi apparatus and vacuoles in wild-type cells, but localization was predominantly at the plasma membrane in Δpub1 cells. Fur4 was necessary for the utilization of extracellular uracil, cytosine, or UMP. Uracil uptake activity increased in the Δpub1 strain in a Fur4-dependent manner. In addition, uracil starvation was critical for induction of cell lysis of Δura4 strains and uracil supplementation suppressed lysis. In summary, the increased uracil uptake ability of Δpub1 cells, where Fur4 was predominantly localized to the plasma membrane, resulted in suppression of cell lysis in the Δura4 background.

No MeSH data available.


Related in: MedlinePlus