Subcellular metal imaging identifies dynamic sites of Cu accumulation in Chlamydomonas [electronic resource]

• Ngôn ngữ: eng
• Ký hiệu phân loại: 541.3 Miscellaneous topics in physical chemistry
• Thông tin xuất bản: Livermore, Calif : Oak Ridge, Tenn. : Lawrence Livermore National Laboratory ; Distributed by the Office of Scientific and Technical Information, U.S. Dept. of Energy, 2014
• Mô tả vật lý: Size: p. 1034-1042 : , digital, PDF file.
• Bộ sưu tập: Metadata
• ID: 261326
• Chủ đề: 1. 37 inorganic, organic, physical and analytical chemistry; 2. 47 other instrumentation; 3. 59 basic biological sciences; 4. 60 applied life sciences; 5. Bacteria; 7. Bioinorganic chemistry; 8. Et al; 9. Membrane trafficking; 11. Metals

Tóm tắt

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.