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Increased phosphate transport of A rabidopsis thaliana P ht1;1 by site‐directed mutagenesis of tyrosine 312 may be attributed to the disruption of homomeric interactions
Author(s) -
Fontenot Elena B.,
Ditusa Sandra Feuer,
Kato Naohiro,
Olivier Danielle M.,
Dale Renee,
Lin WeiYi,
Chiou TzyyJen,
Macnaughtan Megan A.,
Smith Aaron P.
Publication year - 2015
Publication title -
plant, cell and environment
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.646
H-Index - 200
eISSN - 1365-3040
pISSN - 0140-7791
DOI - 10.1111/pce.12522
Subject(s) - homomeric , transporter , heterologous expression , mutagenesis , tyrosine , biochemistry , biology , microbiology and biotechnology , chemistry , mutant , recombinant dna , gene , protein subunit
Abstract Members of the P ht1 family of plant phosphate ( P i) transporters play vital roles in P i acquisition from soil and in planta P i translocation to maintain optimal growth and development. The study of the specificities and biochemical properties of Pht1 transporters will contribute to improving the current understanding of plant phosphorus homeostasis and use‐efficiency. In this study, we show through split in vivo interaction methods and in vitro analysis of microsomal root tissues that A rabidopsis thaliana P ht1;1 and P ht1;4 form homomeric and heteromeric complexes. Transient and heterologous expression of the P ht1;1 variants, P ht1;1 Y312D , P ht1;1 Y312A and P ht1;1 Y312F , was used to analyse the role of a putative P i binding residue ( T yr 312) in P ht1;1 transporter oligomerization and function. The homomeric interaction among P ht1;1 proteins was disrupted by mutation of Tyr 312 to A sp, but not to A la or P he. In addition, the P ht1;1 Y312D variant conferred enhanced P i transport when expressed in yeast cells. In contrast, mutation of T yr 312 to A la or P he did not affect P ht1;1 transport kinetics. Our study demonstrates that modifications to the P ht1;1 higher‐order structure affects P i transport, suggesting that oligomerization may serve as a regulatory mechanism for modulating P i uptake.