Copper is an essential micronutrient because of its role in enzymes that catalyze redox reactions. In humans, acquired copper-deficiency is rare because of the low daily requirement of copper, but copper-deficiency can accompany malnutrition, be associated with genetic disorders like Menkes syndrome or result from overconsumption of zinc supplements. And marginal copper deficiency, a contributing factor in cardiovascular disease, may not be uncommon. The long-term objective of this project is to i) discover the adaptive biochemical changes in copper-deficient cells in the context of specific cuproenzyme-containing pathways, ii) dissect the underlying regulatory mechanisms for achieving these changes, and iii) understand the physiological rationale for the adaptive modifications. Chlamydomonas reinhardtii is the model organism for the study because the well-defined synthetic growth medium facilitates studies of trace element homeostasis, and the full power of classical biochemical and genetic approaches can be combined with state of the art genomic and proteomic methods. The previous studies of copper-deficiency responses in Chlamydomonas established the concept of """"""""back up"""""""" copper-independent enzymes that are expressed in -Cu cells to compensate for loss of function of cuproenzymes (e.g. cyt c6, as a back up for plastocyanin and Crd2 as a back up for the multicopper ferroxidase), and led to the discovery of Crrl, a novel DNA binding protein that is required for all known copper-deficiency responses and is involved also in maintaining copper homeostasis in a copper replete cell. In this project period, the investigators will: 1) identify CRD2, which is required for high affinity iron uptake in a copper-deficient cell, determine its biochemical function in relation to Fox1 (ferroxidase) and Ftr1 (iron permease) function, and monitor its expression and sub-cellular location in response to copper and iron nutrition; 2) dissect 3 domains in the copper regulator Crrl - the DNA-binding SBP domain, ankyrin repeats and the Cys-rich C-terminus - by mutagenesis and in vivo and in vitro functional analysis including CuRE binding, metal binding and redox state, and determine the pattern of copper-dependent Crrl regulation and location, to develop a model for its action as a regulator of copper nutrition and hypoxia; and 3) identify novel targets of copper-deficiency by specialized oligonucleotide microarray analyses of -Cu vs. +Cu cells and err I vs. wild-type cells, in parallel with sub-proteomic gel- and multi-dimensional chromatography-based analyses of copper-replete vs. copper-deficient cells.

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Project (R01)
Project #
5R01GM042143-16
Application #
7227171
Study Section
Integrative Nutrition and Metabolic Processes Study Section (INMP)
Program Officer
Anderson, James J
Project Start
1989-06-01
Project End
2009-03-31
Budget Start
2007-04-01
Budget End
2008-03-31
Support Year
16
Fiscal Year
2007
Total Cost
$442,474
Indirect Cost
Name
University of California Los Angeles
Department
Chemistry
Type
Schools of Arts and Sciences
DUNS #
092530369
City
Los Angeles
State
CA
Country
United States
Zip Code
90095
Kumar, Dhivya; Strenkert, Daniela; Patel-King, Ramila S et al. (2017) A bioactive peptide amidating enzyme is required for ciliogenesis. Elife 6:
Blaby-Haas, Crysten E; Merchant, Sabeeha S (2017) Regulating cellular trace metal economy in algae. Curr Opin Plant Biol 39:88-96
Reyes, Vincent C; Spitzmiller, Melissa R; Hong-Hermesdorf, Anne et al. (2016) Copper status of exposed microorganisms influences susceptibility to metallic nanoparticles. Environ Toxicol Chem 35:1148-58
Blaby-Haas, Crysten E; Castruita, Madeli; Fitz-Gibbon, Sorel T et al. (2016) Ni induces the CRR1-dependent regulon revealing overlap and distinction between hypoxia and Cu deficiency responses in Chlamydomonas reinhardtii. Metallomics 8:679-91
Strenkert, Daniela; Limso, Clariss Ann; Fatihi, Abdelhak et al. (2016) Genetically Programmed Changes in Photosynthetic Cofactor Metabolism in Copper-deficient Chlamydomonas. J Biol Chem 291:19118-31
Kumar, Dhivya; Blaby-Haas, Crysten E; Merchant, Sabeeha S et al. (2016) Early eukaryotic origins for cilia-associated bioactive peptide-amidating activity. J Cell Sci 129:943-56
Yang, Wenqiang; Wittkopp, Tyler M; Li, Xiaobo et al. (2015) Critical role of Chlamydomonas reinhardtii ferredoxin-5 in maintaining membrane structure and dark metabolism. Proc Natl Acad Sci U S A 112:14978-83
Pérez-Martín, Marta; Blaby-Haas, Crysten E; Pérez-Pérez, María Esther et al. (2015) Activation of Autophagy by Metals in Chlamydomonas reinhardtii. Eukaryot Cell 14:964-73
Kropat, Janette; Gallaher, Sean D; Urzica, Eugen I et al. (2015) Copper economy in Chlamydomonas: prioritized allocation and reallocation of copper to respiration vs. photosynthesis. Proc Natl Acad Sci U S A 112:2644-51
Barahimipour, Rouhollah; Strenkert, Daniela; Neupert, Juliane et al. (2015) Dissecting the contributions of GC content and codon usage to gene expression in the model alga Chlamydomonas reinhardtii. Plant J 84:704-17

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