title: Studies on the roles of clathrin-mediated membrane trafficking and zinc transporter Cis4 in the transport of GPI-anchored proteins in fission yeast.
abstract: We previously identified Cis4, a zinc transporter belonging to the cation diffusion facilitator protein family, and we demonstrated that Cis4 is implicated in Golgi membrane trafficking in fission yeast. Here, we identified three glycosylphosphatidylinositol (GPI)-anchored proteins, namely Ecm33, Aah3, and Gaz2, as multicopy suppressors of the MgCl(2)-sensitive phenotype of cis4-1 mutant. The phenotypes of ecm33, aah3 and gaz2 deletion cells were distinct from each other, and Cis4 overexpression suppressed Δecm33 phenotypes but did not suppress Δaah3 defects. Notably, green fluorescent protein-tagged Ecm33, which was observed at the cell surface in wild-type cells, mostly localized as intracellular dots that are presumed to be the Golgi and endosomes in membrane-trafficking mutants, including Δapm1, ypt3-i5, and chc1-1 mutants. Interestingly, all these membrane-trafficking mutants showed hypersensitivity to BE49385A, an inhibitor of Its8 that is involved in GPI-anchored protein synthesis. Taken together, these results suggest that GPI-anchored proteins are transported through a clathrin-mediated post-Golgi membrane trafficking pathway and that zinc transporter Cis4 may play roles in membrane trafficking of GPI-anchored proteins in fission yeast.
authors: Division of Molecular Pharmacology and Pharmacogenomics, Department of Biochemistry and Molecular Biology, Kobe University Graduate School of Medicine, Kobe, Japan.
authors: Wurentuya
authors: W
authors: Jaiseng
authors: Yue
authors: Y
authors: Fang
authors: Yan
authors: Y
authors: Ma
authors: Reiko
authors: R
authors: Sugiura
authors: Takayoshi
authors: T
authors: Kuno
mesh_terms: D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism*; D027682:Cation Transport Proteins / Q000235:genetics / Q000378:metabolism*; D002462:Cell Membrane / Q000378:metabolism*; D002966:Clathrin / Q000378:metabolism*; D005800:Genes, Fungal; D042541:Intracellular Space / Q000378:metabolism; D010641:Phenotype; D021381:Protein Transport; D012568:Schizosaccharomyces / Q000166:cytology* / Q000378:metabolism; D029702:Schizosaccharomyces pombe Proteins / Q000235:genetics / Q000378:metabolism*; D017384:Sequence Deletion
chemical_list: D002352:Carrier Proteins; D027682:Cation Transport Proteins; C577190:Cis4 protein, S pombe; D002966:Clathrin; D029702:Schizosaccharomyces pombe Proteins; C017800:zinc-binding protein