RRC ID 74528
Author Blaby-Haas CE, Padilla-Benavides T, Stübe R, Argüello JM, Merchant SS.
Title Evolution of a plant-specific copper chaperone family for chloroplast copper homeostasis.
Journal Proc Natl Acad Sci U S A
Abstract 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. 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. 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.
Volume 111(50)
Pages E5480-7
Published 2014-12-16
DOI 10.1073/pnas.1421545111
PII 1421545111
PMID 25468978
PMC PMC4273408
MeSH Arabidopsis / genetics* Arabidopsis Proteins / genetics* Arabidopsis Proteins / metabolism Chlamydomonas reinhardtii / genetics Chloroplast Proton-Translocating ATPases / metabolism Chloroplasts / metabolism Chloroplasts / physiology* Cloning, Molecular Computational Biology Copper / metabolism* Evolution, Molecular* Homeostasis / physiology* Immunoblotting Metallochaperones / genetics* Metallochaperones / metabolism Superoxide Dismutase / metabolism
IF 9.412
Arabidopsis / Cultured plant cells, genes pda19661 pda04914