Open AccessE3 Ubiquitin Ligase Pub1 Is implicated in Endocytosis of a GPI-Anchored Protein Ecm33 in Fission Yeast
Author(s) -
Yue Fang,
Wurentuya Jaiseng,
Yan Ma,
Lingling Hu,
Shizuka Yamazaki,
Xibo Zhang,
Tsutomu Hayafuji,
Lin Shi,
Toshiki Kuno
Publication year - 2014
Publication title -
plos one
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.99
H-Index - 332
ISSN - 1932-6203
DOI - 10.1371/journal.pone.0085238
Subject(s) - ubiquitin ligase , biology , microbiology and biotechnology , schizosaccharomyces , schizosaccharomyces pombe , endosome , endocytosis , ubiquitin , wild type , ubiquitin conjugating enzyme , mutant , cell , gene , genetics , intracellular
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 Δ pub1 cells. The Δ pub1 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.