di-Cysteine motifs in the C-terminus of plant HMA4 proteins confer nanomolar affinity for zinc and are essential for HMA4 function in vivo
Gilles Lekeux, Clementine Laurent, Marine Joris, Alice Jadoul, Dan Jiang, Bernard Bosman, Monique Carnol, Patrick Motte, Zhiguang Xiao, Moreno Galleni, Marc Hanikenne
Journal of Experimental Botany | OXFORD UNIV PRESS | Published : 2018
The PIB 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-Cy..View full abstract
Awarded by Fonds de la Recherche Scientiftque - FNRS
Awarded by University of Liege
Awarded by Belgian Program on Interuniversity Attraction Poles (IAP)
We thank Gianinarco Mastrosanti, Arnaud Degueldre and Marie Schloesser for technical support. We also thank Dr Ute Krdmer for helpful discussions. Funding was provided by the "Fonds de la Recherche Scientiftque - FNRS" (FRFC-2.4583.08, PDR-T0206.13; MH, MG), the University of Liege (SFRD-12/03; MH) and the Belgian Program on Interuniversity Attraction Poles (IAP no. P7/44; MG, MH). MH is Research Associate of the FNRS. GL thanks the FRIA for his PhD fellowship.