Evolution of a plant-specific copper chaperone family for chloroplast copper homeostasis

Journal Article · Mon Dec 01 23:00:00 EST 2014 · Proceedings of the National Academy of Sciences of the United States of America

DOI: https://doi.org/10.1073/pnas.1421545111 · OSTI ID:1348351

Blaby-Haas, Crysten E. ^[1]; Padilla-Benavides, Teresita ^[2]; Stübe, Roland ^[3]; Argüello, José M. ^[2]; Merchant, Sabeeha S. ^[4]

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1. Univ. of California, Los Angeles, CA (United States). Dept. of Chemistry and Biochemistry; DOE Office of Scientific and Technical Information (OSTI)
2. Worcester Polytechnic Inst., MA (United States). Dept. of Chemistry and Biochemistry
3. Univ. of California, Los Angeles, CA (United States). Dept. of Chemistry and Biochemistry
4. Univ. of California, Los Angeles, CA (United States). Dept. of Chemistry and Biochemistry. Inst. of Genomics and Proteomics

Metallochaperones traffic copper (Cu⁺) from its point of entry at the plasma membrane to its destination. In plants, one destination is the chloroplast, which houses plastocyanin, a Cu-dependent electron transfer protein involved in photosynthesis. In this paper, we present a previously unidentified Cu⁺ chaperone that evolved early in the plant lineage by an alternative-splicing event of the pre-mRNA encoding the chloroplast P-type ATPase in Arabidopsis 1 (PAA1). In several land plants, recent duplication events created a separate chaperone-encoding gene coincident with loss of alternative splicing. The plant-specific Cu⁺ chaperone delivers Cu⁺ with specificity for PAA1, which is flipped in the envelope relative to prototypical bacterial ATPases, compatible with a role in Cu⁺ import into the stroma and consistent with the canonical catalytic mechanism of these enzymes. The ubiquity of the chaperone suggests conservation of this Cu⁺-delivery mechanism and provides a unique snapshot into the evolution of a Cu⁺ distribution pathway. Finally, we also provide evidence for an interaction between PAA2, the Cu⁺-ATPase in thylakoids, and the Cu⁺-chaperone for Cu/Zn superoxide dismutase (CCS), uncovering a Cu⁺ network that has evolved to fine-tune Cu⁺ distribution.

• Research Organization: Univ. of California, Los Angeles, CA (United States)
• Sponsoring Organization: USDOE Office of Science (SC), Biological and Environmental Research (BER) (SC-23); National Inst. of Health (NIH) (United States); National Science Foundation (NSF) (United States)
• Contributing Organization: Worcester Polytechnic Inst., MA (United States)
• Grant/Contract Number: FC02-02ER63421
• OSTI ID: 1348351
• Journal Information: Proceedings of the National Academy of Sciences of the United States of America, Journal Name: Proceedings of the National Academy of Sciences of the United States of America Journal Issue: 50 Vol. 111; ISSN 0027-8424
• Publisher: National Academy of Sciences, Washington, DC (United States)Copyright Statement
• Country of Publication: United States
• Language: English