title: Expression profile of the genes for rice cation/H+ exchanger family and functional analysis in yeast.
abstract: We identified five cation/H(+) exchangers (CAX) from rice, and phylogenetically divided them into two clusters. Gene expression and absolute amounts of mRNA in different organs were analyzed by real-time PCR. OsCAX1a showed high expression in almost all organs. OsCAX1b and OsCAX1c were detected in a limited number of organs and their expression levels were very low. The mRNA levels of OsCAX2 and OsCAX3 varied with the organ. OsCAXs were heterologously expressed in yeast to characterize the ion transport activity. All exchangers, except for OsCAX2, conferred tolerance to calcium. OsCAX1a and OsCAX3 conferred tolerance to manganese. The diversity of expression sites and substrates suggest the broad range function of CAX.
authors.affiliation: Laboratory of Cell Dynamics, Graduate School of Bioagricultural Sciences, Nagoya University, Furocho, Chikusa-ku, Japan.
authors.forename: Takehiro
authors.initials: T
authors.lastname: Kamiya
authors.forename: Taro
authors.initials: T
authors.lastname: Akahori
authors.forename: Masayoshi
authors.initials: M
authors.lastname: Maeshima
mesh_terms: D000595:Amino Acid Sequence; D017920:Antiporters / Q000737:chemistry / Q000235:genetics*; D001483:Base Sequence; D002412:Cations; D017931:DNA Primers; D020869:Gene Expression Profiling; D008969:Molecular Sequence Data; D012275:Oryza / Q000235:genetics*; D011522:Protons; D012441:Saccharomyces cerevisiae / Q000235:genetics*; D017386:Sequence Homology, Amino Acid
chemical_list: D017920:Antiporters; D002412:Cations; D017931:DNA Primers; D011522:Protons