title: TcOPT3, a member of oligopeptide transporters from the hyperaccumulator Thlaspi caerulescens, is a novel Fe/Zn/Cd/Cu transporter.
abstract: BACKGROUND
  Thlaspi caerulescens is a natural selected heavy metal hyperaccumulator that can not only tolerate but also accumulate extremely high levels of heavy metals in the shoots. Thus, to identify the transportors involved in metal long-distance transportation is very important for understanding the mechanism of heavy metal accumulation in this hyperaccumulator.
  
  
  RESULTS
  We cloned and characterized a novel gene TcOPT3 of OPT family from T. caerulescens. TcOPT3 was pronouncedly expressed in aerial parts, including stem and leaf. Moreover, in situ hybridization analyses showed that TcOPT3 expressed in the plant vascular systems, especially in the pericycle cells that may be involved in the long-distance transportation. The expression of TcOPT3 was highly induced by iron (Fe) and zinc (Zn) deficiency, especially in the stem and leaf. Sub-cellular localization showed that TcOPT3 was a plasma membrane-localized protein. Furthermore, heterogonous expression of TcOPT3 by mutant yeast (Saccharomyces cerevisiae) complementation experiments demonstrated that TcOPT3 could transport Fe(2+) and Zn(2+). Moreover, expression of TcOPT3 in yeast increased metal (Fe, Zn, Cu and Cd) accumulation and resulted in an increased sensitivity to cadmium (Cd) and copper (Cu).
  
  
  CONCLUSIONS
  Our data demonstrated that TcOPT3 might encode an Fe/Zn/Cd/Cu influx transporter with broad-substrate. This is the first report showing that TcOPT3 may be involved in metal long-distance transportation and contribute to the heavy metal hyperaccumulation.
authors: College of Environmental and Resource Sciences, Zhejiang University, Hanzhou, China.
authors: Yi Ting
authors: YT
authors: Hu
authors: Feng
authors: F
authors: Ming
authors: Wei Wei
authors: WW
authors: Chen
authors: Jing Ying
authors: JY
authors: Yan
authors: Zheng Yu
authors: ZY
authors: Xu
authors: Gui Xin
authors: GX
authors: Li
authors: Chun Yan
authors: CY
authors: Xu
authors: Jian Li
authors: JL
authors: Yang
authors: Shao Jian
authors: SJ
authors: Zheng
mesh_terms: D000595:Amino Acid Sequence; D001692:Biological Transport; D002104:Cadmium / Q000378:metabolism*; D003300:Copper / Q000378:metabolism*; D018744:DNA, Plant / Q000235:genetics; D018506:Gene Expression Regulation, Plant; D005816:Genetic Complementation Test; D017403:In Situ Hybridization; D007501:Iron / Q000378:metabolism*; D026901:Membrane Transport Proteins / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D008969:Molecular Sequence Data; D009842:Oligopeptides / Q000378:metabolism*; D010802:Phylogeny; D010940:Plant Proteins; D060888:Real-Time Polymerase Chain Reaction; D012441:Saccharomyces cerevisiae; D013347:Subcellular Fractions; D031227:Thlaspi / Q000254:growth & development / Q000378:metabolism*; D015032:Zinc / Q000378:metabolism*
chemical_list: D018744:DNA, Plant; D026901:Membrane Transport Proteins; D009842:Oligopeptides; D010940:Plant Proteins; D002104:Cadmium; D003300:Copper; D007501:Iron; D015032:Zinc