HMA1, a new Cu-ATPase of the chloroplast envelope, is essential for growth under adverse light conditions. - Inserm - Institut national de la santé et de la recherche médicale Access content directly
Journal Articles Journal of Biological Chemistry Year : 2006

HMA1, a new Cu-ATPase of the chloroplast envelope, is essential for growth under adverse light conditions.

Abstract

Although ions play important roles in the cell and chloroplast metabolism, little is known about ion transport across the chloroplast envelope. Using a proteomic approach specifically targeted to the Arabidopsis chloroplast envelope, we have identified HMA1, which belongs to the metal-transporting P1B-type ATPases family. HMA1 is mainly expressed in green tissues, and we validated its chloroplast envelope localization. Yeast expression experiments demonstrated that HMA1 is involved in copper homeostasis and that deletion of its N-terminal His-domain partially affects the metal transport. Characterization of hma1 Arabidopsis mutants revealed a lower chloroplast copper content and a diminution of the total chloroplast superoxide dismutase activity. No effect was observed on the plastocyanin content in these lines. The hma1 insertional mutants grew like WT plants in standard condition but presented a photosensitivity phenotype under high light. Finally, direct biochemical ATPase assays performed on purified chloroplast envelope membranes showed that the ATPase activity of HMA1 is specifically stimulated by copper. Our results demonstrate that HMA1 offers an additional way to the previously characterized chloroplast envelope Cu-ATPase PAA1 to import copper in the chloroplast.
Embargoed file
Embargoed file
Visibility date is undetermined

Dates and versions

inserm-00764319 , version 1 (12-12-2012)

Licence

Copyright

Identifiers

Cite

Daphné Seigneurin-Berny, Antoine Gravot, Pascaline Auroy, Christophe Mazard, Alexandra Kraut, et al.. HMA1, a new Cu-ATPase of the chloroplast envelope, is essential for growth under adverse light conditions.. Journal of Biological Chemistry, 2006, 281 (5), pp.2882-92. ⟨10.1074/jbc.M508333200⟩. ⟨inserm-00764319⟩
444 View
2 Download

Altmetric

Share

Gmail Facebook X LinkedIn More