title: Regulation of copper homeostasis by Cuf1 associates with its subcellular localization in the pathogenic yeast Cryptococcus neoformans H99.
abstract: Here, we present further characterization of cryptococcal CUF1 in copper homeostasis. We demonstrated that CUF1 was involved both in copper acquisition and in copper detoxification in response to copper variation. This was verified by direct measurement of the quantity of intracellular copper with flame atomic absorption spectrometry (FAAS) and molecular evidence. In copper-limited growth, the mutant cuf1Δ exhibited copper deficiency, growth defect on glycerol and sensitivity to hydrogen peroxide and methionine. A novel function of cryptococcal CUF1 is revealed in copper detoxification when copper is in excess. The mutant cuf1Δ showed severe hypersensitivity to exogenous copper, while a high level of copper was accumulated shown by FAAS, suggesting that CUF1 may be required in copper export events. On cloning of cDNA, it was found that Cuf1 distinguishably harbors functional elements that are found in Ace1 and Mac1 of Saccharomyces cerevisiae. The regulation of copper homeostasis by Cuf1 is realized by its subcellular localization. Epifluorescence microscopy observed that, upon copper depletion, Cuf1 was localized exclusively to the nucleus as an activator for CTR4 transcription, while it was located to the cell periphery in the presence of exogenous copper. This work reveals a unique copper regulator and may provide insights into the copper metabolism in fungi.
authors.affiliation: National Key Program of Microbiology, Department of Microbiology, College of Life Sciences, Nankai University, Tianjin, China.
authors.forename: Nan
authors.initials: N
authors.lastname: Jiang
authors.forename: Xiaoguang
authors.initials: X
authors.lastname: Liu
authors.forename: Jiao
authors.initials: J
authors.lastname: Yang
authors.forename: Zhongming
authors.initials: Z
authors.lastname: Li
authors.forename: Jiao
authors.initials: J
authors.lastname: Pan
authors.forename: Xudong
authors.initials: X
authors.lastname: Zhu
mesh_terms: D000595:Amino Acid Sequence; D001483:Base Sequence; D002374:Catalase / Q000378:metabolism; D002467:Cell Nucleus / Q000378:metabolism; D003300:Copper / Q000032:analysis / Q000378:metabolism*; D003455:Cryptococcus neoformans / Q000235:genetics / Q000378:metabolism*; D003593:Cytoplasm / Q000378:metabolism; D018076:DNA, Complementary / Q000235:genetics; D005656:Fungal Proteins / Q000235:genetics / Q000378:metabolism*; D015966:Gene Expression Regulation, Fungal; D006706:Homeostasis; D008969:Molecular Sequence Data; D018384:Oxidative Stress; D012331:RNA, Fungal / Q000235:genetics; D011993:Recombinant Fusion Proteins; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D017384:Sequence Deletion; D013054:Spectrophotometry, Atomic / Q000379:methods; D013312:Stress, Physiological; D013482:Superoxide Dismutase / Q000378:metabolism; D015534:Trans-Activators / Q000235:genetics / Q000378:metabolism*
chemical_list: D018076:DNA, Complementary; D005656:Fungal Proteins; D012331:RNA, Fungal; D011993:Recombinant Fusion Proteins; D015534:Trans-Activators; D003300:Copper; D002374:Catalase; D013482:Superoxide Dismutase