A CDC25 homologue from rice functions as an arsenate reductase

Enzymatic reduction of arsenate to arsenite is the first step in arsenate metabolism in all organisms studied. The rice genome contains two ACR2-like genes, OsACR2.1 and OsACR2.2, which may be involved in regulating arsenic metabolism in rice. Here, we cloned both OsACR2 genes and expressed them in...

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Veröffentlicht in:The New phytologist. - 1979. - 174(2007), 2 vom: 27., Seite 311-321
1. Verfasser: Duan, Gui-Lan (VerfasserIn)
Weitere Verfasser: Zhou, Yao, Tong, Yi-Ping, Mukhopadhyay, Rita, Rosen, Barry P, Zhu, Yong-Guan
Format: Online-Aufsatz
Sprache:English
Veröffentlicht: 2007
Zugriff auf das übergeordnete Werk:The New phytologist
Schlagworte:Journal Article Research Support, N.I.H., Extramural Research Support, Non-U.S. Gov't Arsenates Phosphates Arsenate Reductases EC 1.20.- cdc25 Phosphatases EC 3.1.3.48 arsenic acid N7CIZ75ZPN
Beschreibung
Zusammenfassung:Enzymatic reduction of arsenate to arsenite is the first step in arsenate metabolism in all organisms studied. The rice genome contains two ACR2-like genes, OsACR2.1 and OsACR2.2, which may be involved in regulating arsenic metabolism in rice. Here, we cloned both OsACR2 genes and expressed them in an Escherichia coli strain in which the arsC gene was deleted and in a yeast (Saccharomyces cerevisiae) strain with a disrupted ACR2 gene. OsACR2.1 complemented the arsenate hypersensitive phenotype of E. coli and yeast. OsACR2.2 showed much less ability to complement. The gene products were purified and demonstrated to reduce arsenate to arsenite in vitro, and both exhibited phosphatase activity. In agreement with the complementation results, OsACR2.1 exhibited higher reductase activity than OsACR2.2. Mutagenesis of cysteine residues in the putative active site HC(X)(5)R motif led to nearly complete loss of both phosphatase and arsenate reductase activities. In planta expression of OsACR2.1 increased dramatically after exposure to arsenate. OsACR2.2 was observed only in roots following arsenate exposure, and its expression was less than OsACR2.1
Beschreibung:Date Completed 18.06.2007
Date Revised 14.04.2021
published: Print
Citation Status MEDLINE
ISSN:1469-8137
DOI:10.1111/j.1469-8137.2007.02009.x