Journal
JOURNAL OF EXPERIMENTAL BOTANY
Volume 69, Issue 22, Pages 5547-5560Publisher
OXFORD UNIV PRESS
DOI: 10.1093/jxb/ery311
Keywords
Arabidopsis; HMA4; hyperaccumulation; in vivo imaging; metal binding; metal-protein interaction; P-type ATPase; zinc
Categories
Funding
- Fonds de la Recherche Scientiftque - FNRS [FRFC-2.4583.08, PDR-T0206.13]
- University of Liege [SFRD-12/03]
- Belgian Program on Interuniversity Attraction Poles (IAP) [P7/44]
- FRIA
Ask authors/readers for more resources
The P-IB ATPase heavy metal ATPase 4 (HMA4) has a central role in the zinc homeostasis network of Arabidopsis thaliana. This membrane protein loads metal from the pericycle cells into the xylem in roots, thereby allowing root to shoot metal translocation. Moreover, HMA4 is key for zinc hyperaccumulation as well as zinc and cadmium hypertolerance in the pseudometallophyte Arabidopsis halleri. The plant-specific cytosolic C-terminal extension of HMA4 is rich in putative metal-binding residues and has substantially diverged between A. thaliana and A. halleri. To clarify the function of the domain in both species, protein variants with truncated C-terminal extension, as well as with mutated di-Cys motifs and/or a His-stretch, were functionally characterized. We show that di-Cys motifs, but not the His-stretch, contribute to high affinity zinc binding and function in planta. We suggest that the HMA4 C-terminal extension is at least partly responsible for protein targeting to the plasma membrane. Finally, we reveal that the C-terminal extensions of both A. thaliana and A. hailed HMA4 proteins share similar function, despite marginally different zinc-binding capacity.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available