Cell Lysis in S. pombe ura4 Mutants Is Suppressed by Loss of Functional Pub1, Which Regulates the Uracil Transporter Fur4: e0141796

• Published in: PloS one 2015-11, Vol.10 (11)
• Main Authors: Nishino, Kohei, Kushima, Misaki, Matsuo, Yuzy, Matsuo, Yasuhiro, Kawamukai, Makoto
• Format: Article
• Language: English
• Subjects: Schizosaccharomyces pombe
• ISSN: 1932-6203
• DOI: 10.1371/journal.pone.0141796

Schizosaccharomyces pombe [delta]ura4 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 [delta]ura4 cells. The [delta]pub1 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 [delta]pub1 cells. Fur4 was necessary for the utilization of extracellular uracil, cytosine, or UMP. Uracil uptake activity increased in the [delta]pub1 strain in a Fur4-dependent manner. In addition, uracil starvation was critical for induction of cell lysis of [delta]ura4 strains and uracil supplementation suppressed lysis. In summary, the increased uracil uptake ability of [delta]pub1 cells, where Fur4 was predominantly localized to the plasma membrane, resulted in suppression of cell lysis in the [delta]ura4 background.