Poster: Heavy metals & phytoremediation

Abs # 46: Evidence of adaptative variation in metallothionein (MT3) of the hyperaccumulator Thlaspi caerulescens

Presenter:	Roosens, Nancy HCJ, nroosens@ulb.ac.be
Authors	Roosens, Nancy HCJ (A)   Bernard, Catherine  (A)   Leplae, Raphael  (B)   Verbruggen, Nathalie  (A)
Affiliations:	(A): Laboratoire de Physiologie et Génétique Moléculaire des Plantes, Université Libre de Bruxelles (B): Service de Conformation des Macromolécules Biologiques et bioinformatique, Université Libre de Bruxelles

Metallothioneins chelate metals and consequently may be a control point of metal homeostasis. Homologous to type 3 metallothioneins, TcMT3, was isolated from the Cd/Zn hyperaccumulator, Thlaspi caerulescens. TcMT3 amino acid sequence showed modifications in the Cys position when compared with its Arabidopsis orthologue. A structural model established that the MT3 carboxyterminal domain is similar to the β domain of animal metallothioneins and predicts a smaller cavity to chelate metals for A. thaliana than for T. caerulescens. Functional testing in yeast and Northern blot analysis added further evidence for adaptative variations of MT3 for the maintenance of Cu homeostasis in a metal hyperaccumulator.