title: Subcellular metal imaging identifies dynamic sites of Cu accumulation in Chlamydomonas.
abstract: We identified a Cu-accumulating structure with a dynamic role in intracellular Cu homeostasis. During Zn limitation, Chlamydomonas reinhardtii hyperaccumulates Cu, a process dependent on the nutritional Cu sensor CRR1, but it is functionally Cu deficient. Visualization of intracellular Cu revealed major Cu accumulation sites coincident with electron-dense structures that stained positive for low pH and polyphosphate, suggesting that they are lysosome-related organelles. Nano-secondary ion MS showed colocalization of Ca and Cu, and X-ray absorption spectroscopy was consistent with Cu(+) accumulation in an ordered structure. Zn resupply restored Cu homeostasis concomitant with reduced abundance of these structures. Cu isotope labeling demonstrated that sequestered Cu(+) became bioavailable for the synthesis of plastocyanin, and transcriptome profiling indicated that mobilized Cu became visible to CRR1. Cu trafficking to intracellular accumulation sites may be a strategy for preventing protein mismetallation during Zn deficiency and enabling efficient cuproprotein metallation or remetallation upon Zn resupply.
authors.affiliation: Department of Chemistry and Biochemistry, University of California-Los Angeles, Los Angeles, California, USA.
authors.forename: Anne
authors.initials: A
authors.lastname: Hong-Hermesdorf
authors.affiliation: Department of Chemistry and Biochemistry, University of California-Los Angeles, Los Angeles, California, USA.
authors.forename: Marcus
authors.initials: M
authors.lastname: Miethke
authors.affiliation: Department of Chemistry and Biochemistry, University of California-Los Angeles, Los Angeles, California, USA.
authors.forename: Sean D
authors.initials: SD
authors.lastname: Gallaher
authors.affiliation: Department of Chemistry and Biochemistry, University of California-Los Angeles, Los Angeles, California, USA.
authors.forename: Janette
authors.initials: J
authors.lastname: Kropat
authors.affiliation: 1] Department of Chemistry, University of California-Berkeley, Berkeley, California, USA. [2] Howard Hughes Medical Institute, University of California-Berkeley, Berkeley, California, USA.
authors.forename: Sheel C
authors.initials: SC
authors.lastname: Dodani
authors.affiliation: 1] Department of Chemistry, University of California-Berkeley, Berkeley, California, USA. [2] Howard Hughes Medical Institute, University of California-Berkeley, Berkeley, California, USA.
authors.forename: Jefferson
authors.initials: J
authors.lastname: Chan
authors.affiliation: Department of Pharmaceutical Sciences, Wayne State University, Detroit, Michigan, USA.
authors.forename: Dulmini
authors.initials: D
authors.lastname: Barupala
authors.affiliation: 1] Department of Chemistry, University of California-Berkeley, Berkeley, California, USA. [2] Howard Hughes Medical Institute, University of California-Berkeley, Berkeley, California, USA.
authors.forename: Dylan W
authors.initials: DW
authors.lastname: Domaille
authors.affiliation: Department of Biological Chemistry, University of California-Los Angeles, Los Angeles, California, USA.
authors.forename: Dyna I
authors.initials: DI
authors.lastname: Shirasaki
authors.affiliation: 1] Department of Chemistry and Biochemistry, University of California-Los Angeles, Los Angeles, California, USA. [2] Department of Biological Chemistry, University of California-Los Angeles, Los Angeles, California, USA. [3] Institute for Genomics and Proteomics, University of California-Los Angeles, Los Angeles, USA.
authors.forename: Joseph A
authors.initials: JA
authors.lastname: Loo
authors.affiliation: Chemical Sciences Division, Lawrence Livermore National Laboratory, Livermore, USA.
authors.forename: Peter K
authors.initials: PK
authors.lastname: Weber
authors.affiliation: Chemical Sciences Division, Lawrence Livermore National Laboratory, Livermore, USA.
authors.forename: Jennifer
authors.initials: J
authors.lastname: Pett-Ridge
authors.affiliation: Department of Pharmaceutical Sciences, Wayne State University, Detroit, Michigan, USA.
authors.forename: Timothy L
authors.initials: TL
authors.lastname: Stemmler
authors.affiliation: 1] Department of Chemistry, University of California-Berkeley, Berkeley, California, USA. [2] Howard Hughes Medical Institute, University of California-Berkeley, Berkeley, California, USA.
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: Chang
authors.affiliation: 1] Department of Chemistry and Biochemistry, University of California-Los Angeles, Los Angeles, California, USA. [2] Institute for Genomics and Proteomics, University of California-Los Angeles, Los Angeles, USA.
authors.forename: Sabeeha S
authors.initials: SS
authors.lastname: Merchant
mesh_terms: D002413:Cations, Divalent; D016825:Chlamydomonas reinhardtii / Q000235:genetics / Q000378:metabolism* / Q000648:ultrastructure; D003300:Copper / Q000378:metabolism*; D020869:Gene Expression Profiling; D006706:Homeostasis; D006863:Hydrogen-Ion Concentration; D007553:Isotope Labeling; D007554:Isotopes; D008247:Lysosomes / Q000378:metabolism* / Q000648:ultrastructure; D057054:Molecular Imaging; D010970:Plastocyanin / Q000096:biosynthesis / Q000235:genetics; D011122:Polyphosphates / Q000378:metabolism; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*; D059467:Transcriptome; D015032:Zinc / Q000378:metabolism*
chemical_list: D002413:Cations, Divalent; D007554:Isotopes; D011122:Polyphosphates; D014157:Transcription Factors; D003300:Copper; D010970:Plastocyanin; D015032:Zinc