title: The arsenic hyperaccumulating Pteris vittata expresses two arsenate reductases.
abstract: Enzymatic reduction of arsenate to arsenite is the first known step in arsenate metabolism in all organisms. Although the presence of one mRNA arsenate reductase (PvACR2) has been characterized in gametophytes of P. vittata, no arsenate reductase protein has been directly observed in this arsenic hyperaccumulating fern, yet. In order to assess the possible presence of arsenate reductase in P. vittata, two recombinant proteins, ACR2-His6 and Trx-His6-S-Pv2.5-8 were prepared in Escherichia coli, purified and used to produce polyclonal antibodies. The presence of these two enzymes was evaluated by qRT-PCR, immunoblotting and direct MS analysis. Enzymatic activity was detected in crude extracts. For the first time we detected and identified two arsenate reductase proteins (PvACR2 and Pv2.5-8) in sporophytes and gametophytes of P. vittata. Despite an increase of the mRNA levels for both proteins in roots, no difference was observed at the protein level after arsenic treatment. Overall, our data demonstrate the constitutive protein expression of PvACR2 and Pv2.5-8 in P. vittata tissues and propose their specific role in the complex metabolic network of arsenic reduction.
authors.affiliation: Università del Piemonte Orientale, DiSIT- Dipartimento di Scienze e Innovazione Tecnologica, viale T. Michel 11, 15121 - Alessandria, Novara, Vercelli - Italy.
authors.forename: Patrizia
authors.initials: P
authors.lastname: Cesaro
authors.affiliation: Università del Piemonte Orientale, DiSIT- Dipartimento di Scienze e Innovazione Tecnologica, viale T. Michel 11, 15121 - Alessandria, Novara, Vercelli - Italy.
authors.forename: Chiara
authors.initials: C
authors.lastname: Cattaneo
authors.affiliation: Università del Piemonte Orientale, DiSIT- Dipartimento di Scienze e Innovazione Tecnologica, viale T. Michel 11, 15121 - Alessandria, Novara, Vercelli - Italy.
authors.forename: Elisa
authors.initials: E
authors.lastname: Bona
authors.affiliation: Università del Piemonte Orientale, DiSIT- Dipartimento di Scienze e Innovazione Tecnologica, viale T. Michel 11, 15121 - Alessandria, Novara, Vercelli - Italy.
authors.forename: Graziella
authors.initials: G
authors.lastname: Berta
authors.affiliation: Università del Piemonte Orientale, DiSIT- Dipartimento di Scienze e Innovazione Tecnologica, viale T. Michel 11, 15121 - Alessandria, Novara, Vercelli - Italy.
authors.forename: Maria
authors.initials: M
authors.lastname: Cavaletto
mesh_terms: D000595:Amino Acid Sequence; D053502:Arsenate Reductases / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D001151:Arsenic / Q000378:metabolism*; D018506:Gene Expression Regulation, Plant; D008969:Molecular Sequence Data; D010758:Phosphorus / Q000378:metabolism; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D018517:Plant Roots / Q000378:metabolism; D032495:Pteris / Q000235:genetics* / Q000378:metabolism*
chemical_list: D010940:Plant Proteins; D010758:Phosphorus; D053502:Arsenate Reductases; D001151:Arsenic