title: Molecular cloning and functional analysis of a H(+)-dependent phosphate transporter gene from the ectomycorrhizal fungus Boletus edulis in southwest China.
abstract: Phosphate transporters (PTs), as entry points for phosphorus (P) in organisms, are involved in a number of P nutrition processes such as phosphate uptake, transport, and transfer. In the study, a PT gene 1632 bp long (named BePT) was cloned, identified, and functionally characterized from Boletus edulis. BePT was expected to encode a polypeptide with 543 amino acid residues. The BePT polypeptide belonged to the major facilitator superfamily and showed a high degree of sequence identity to the Pht1 family. A topology model revealed that BePT exhibited 12 transmembrane helices, divided into two halves, and connected by a large hydrophilic loop in the middle. A yeast mutant complementation analysis suggested that BePT was a functional PT which mediated orthophosphate uptake of yeast at micromolar concentrations. Green fluorescent protein-BePT fusion proteins expressed were extensively restricted to the plasma membrane in BePT transformed yeast, and its activity was dependent on electrochemical membrane potential. In vitro, quantitative PCR confirmed that the expression of BePT was significantly upregulated at lower phosphorus availability, which may enhance phosphate uptake and transport under phosphate starvation. Our results suggest that BePT plays a key role in phosphate acquisition in the ectomycorrhizal fungus B. edulis.
authors.affiliation: Laboratory of Conservation and Utilization for Bioresources, Key Laboratory of Microbial Diversity in Southwest China, Ministry of Education, Yunnan University, Kunming, Yunnan Province, PR China.
authors.forename: Junling
authors.initials: J
authors.lastname: Wang
authors.affiliation: Laboratory of Conservation and Utilization for Bioresources, Key Laboratory of Microbial Diversity in Southwest China, Ministry of Education, Yunnan University, Kunming, Yunnan Province, PR China.
authors.forename: Tao
authors.initials: T
authors.lastname: Li
authors.affiliation: Laboratory of Conservation and Utilization for Bioresources, Key Laboratory of Microbial Diversity in Southwest China, Ministry of Education, Yunnan University, Kunming, Yunnan Province, PR China.
authors.forename: Xiaogang
authors.initials: X
authors.lastname: Wu
authors.affiliation: Laboratory of Conservation and Utilization for Bioresources, Key Laboratory of Microbial Diversity in Southwest China, Ministry of Education, Yunnan University, Kunming, Yunnan Province, PR China. Electronic address: zwzhao2001@yahoo.com.cn.
authors.forename: Zhiwei
authors.initials: Z
authors.lastname: Zhao
mesh_terms: D001487:Basidiomycota / Q000145:classification / Q000235:genetics / Q000378:metabolism*; D002681:China; D003001:Cloning, Molecular; D005656:Fungal Proteins / Q000235:genetics* / Q000378:metabolism*; D008969:Molecular Sequence Data; D038821:Mycorrhizae / Q000145:classification / Q000235:genetics / Q000378:metabolism*; D028061:Phosphate Transport Proteins / Q000235:genetics* / Q000378:metabolism*; D010710:Phosphates / Q000378:metabolism; D010802:Phylogeny
chemical_list: D005656:Fungal Proteins; D028061:Phosphate Transport Proteins; D010710:Phosphates
keywords: Gene expression; Heterologous characterization; Phosphate uptake; Plasma membrane phosphate transporter; Yeast