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Title: Subcellular metal imaging identifies dynamic sites of Cu accumulation in Chlamydomonas

Here 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:
 [1] ;  [1] ;  [1] ;  [1] ;  [2] ;  [2] ;  [3] ;  [2] ;  [4] ;  [5] ;  [6] ;  [6] ;  [3] ;  [2] ;  [7]
  1. Univ. of California-Los Angeles, Los Angeles, CA (United States). Dept. of Materials Science and Engineering
  2. Univ. of California-Berkeley, Berkeley, CA (United States). Dept. of Chemistry; Univ. of California-Berkeley, Berkeley, CA (United States). Howard Hughes Medical Inst.
  3. Wayne State Univ., Detroit, MI (United States). Dept. of Pharmaceutical Sciences
  4. Univ. of California-Los Angeles, Los Angeles, CA (United States). Dept. of Biological Chemistry
  5. Univ. of California-Los Angeles, Los Angeles, CA (United States). Dept. of Materials Science and Engineering; Univ. of California-Los Angeles, Los Angeles, CA (United States). Dept. of Biological Chemistry; Univ. of California-Los Angeles, Los Angeles, CA (United States).Inst. for Genomics and Proteomics
  6. Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States). Chemical Sciences Division
  7. Univ. of California-Los Angeles, Los Angeles, CA (United States). Dept. of Materials Science and Engineering; Univ. of California-Los Angeles, Los Angeles, CA (United States).Inst. for Genomics and Proteomics
Publication Date:
OSTI Identifier:
1282166
Grant/Contract Number:
FC02-02ER63421; AC52-07NA27344; T32HL120822; D1242134
Type:
Accepted Manuscript
Journal Name:
Nature Chemical Biology
Additional Journal Information:
Journal Volume: 10; Journal Issue: 12; Journal ID: ISSN 1552-4450
Publisher:
Nature Publishing Group
Research Org:
Lawrence Livermore National Laboratory (LLNL), Livermore, CA (United States)
Sponsoring Org:
USDOE; National Inst. of Health (NIH)
Country of Publication:
United States
Language:
English
Subject:
60 APPLIED LIFE SCIENCES; 47 OTHER INSTRUMENTATION Metals; Membrane trafficking; Membrane trafficking; Bacteria