E3 ubiquitin ligase Pub1 is implicated in endocytosis of a GPI-anchored protein Ecm33 in fission yeast.
We previously identified three glycosylphosphatidylinositol (GPI)-anchored proteins including Ecm33, as multicopy suppressors of the phenotypes of a mutant allele of cis4(+) that encodes a zinc transporter in fission yeast. Here, we further identified two multicopy suppressor genes, ubi1 (+) and ubc4 (+), encoding ubiquitin-ribosomal fusion protein and ubiquitin conjugating enzyme E2, respectively. In addition, Ubi1 or Ubc4 overexpression failed to suppress the phenotypes of the double deletion of cis4 (+) and pub1 (+) gene, which encodes a HECT-type ubiquitin ligase E3. During exponential phase GFP-Ecm33 localized at the growing cell tips of the cell surface and the medial region in wild-type cells. Notably, during the post-exponential and stationary phase, GFP-Ecm33 in wild-type cells was internalized and mostly localized to the Golgi/endosomes, but it was still stably localized at the cell surface in Δpub1 cells. The Δpub1 cells showed osomoremedial phenotypes to various drugs indicating their defects in cell wall integrity. Altogether, our findings reveal a novel role for Pub1 in endocytosis of Ecm33 and regulation of cell wall integrity in fission yeast.
Department of Biopharmaceutics, School of Pharmacy, China Medical University, Shenyang, China ; Division of Molecular Pharmacology and Pharmacogenomics, Department of Biochemistry and Molecular Biology, Kobe University Graduate School of Medicine, Kobe, Japan.
Yue
Y
Fang
Division of Molecular Pharmacology and Pharmacogenomics, Department of Biochemistry and Molecular Biology, Kobe University Graduate School of Medicine, Kobe, Japan ; College of Mongolian Medicine, Inner Mongolia University for the Nationalities, Tongliao, China.
Wurentuya
W
Jaiseng
Division of Molecular Pharmacology and Pharmacogenomics, Department of Biochemistry and Molecular Biology, Kobe University Graduate School of Medicine, Kobe, Japan.
Yan
Y
Ma
Division of Molecular Pharmacology and Pharmacogenomics, Department of Biochemistry and Molecular Biology, Kobe University Graduate School of Medicine, Kobe, Japan.
Lingling
L
Hu
Division of Molecular Pharmacology and Pharmacogenomics, Department of Biochemistry and Molecular Biology, Kobe University Graduate School of Medicine, Kobe, Japan.
Shizuka
S
Yamazaki
Department of Biopharmaceutics, School of Pharmacy, China Medical University, Shenyang, China ; Division of Molecular Pharmacology and Pharmacogenomics, Department of Biochemistry and Molecular Biology, Kobe University Graduate School of Medicine, Kobe, Japan.
Xibo
X
Zhang
Division of Molecular Pharmacology and Pharmacogenomics, Department of Biochemistry and Molecular Biology, Kobe University Graduate School of Medicine, Kobe, Japan.
Tsutomu
T
Hayafuji
Department of Biopharmaceutics, School of Pharmacy, China Medical University, Shenyang, China.
Lin
L
Shi
Department of Biopharmaceutics, School of Pharmacy, China Medical University, Shenyang, China ; Division of Molecular Pharmacology and Pharmacogenomics, Department of Biochemistry and Molecular Biology, Kobe University Graduate School of Medicine, Kobe, Japan.
Takayoshi
T
Kuno
D019703:Calcineurin / Q000378:metabolism; D019731:Carbon-Nitrogen Ligases / Q000378:metabolism*; D002473:Cell Wall / Q000378:metabolism; D004705:Endocytosis; D058685:Genetic Pleiotropy / Q000528:radiation effects*; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D009154:Mutation; D020218:Response Elements / Q000235:genetics; D012568:Schizosaccharomyces / Q000166:cytology* / Q000235:genetics / Q000378:metabolism*; D029702:Schizosaccharomyces pombe Proteins / Q000235:genetics / Q000378:metabolism*; D014158:Transcription, Genetic; D044763:Ubiquitin-Conjugating Enzymes / Q000235:genetics / Q000378:metabolism
C000591535:ECM33 protein, S pombe; D008565:Membrane Proteins; D029702:Schizosaccharomyces pombe Proteins; D044763:Ubiquitin-Conjugating Enzymes; D019703:Calcineurin; D019731:Carbon-Nitrogen Ligases; C098922:Pub1 protein, S pombe