Phylogenetic Relationships within Cation Transporter Families of Arabidopsis

Abstract

Uptake and translocation of cationic nutrients play essential roles in physiological processes including plant growth, nutrition, signal transduction, and development. Approximately 5% of the Arabidopsis genome appears to encode membrane transport proteins. These proteins are classified in 46 unique families containing approximately 880 members. In addition, several hundred putative transporters have not yet been assigned to families. In this paper, we have analyzed the phylogenetic relationships of over 150 cation transport proteins. This analysis has focused on cation transporter gene families for which initial characterizations have been achieved for individual members, including potassium transporters and channels, sodium transporters, calcium antiporters, cyclic nucleotide-gated channels, cation diffusion facilitator proteins, natural resistance-associated macrophage proteins (NRAMP), and Zn-regulated transporter Fe-regulated transporterlike proteins. Phylogenetic trees of each family define the evolutionary relationships of the members to each other. These families contain numerous members, indicating diverse functions in vivo. Closely related isoforms and separate subfamilies exist within many of these gene families, indicating possible redundancies and specialized functions. To facilitate their further study, the PlantsT database (http://plantst.sdsc.edu) has been created that includes alignments of the analyzed cation transporters and their chromosomal locations.

Dissection of the Control of Anion Homeostasis by Associative Transcriptomics in Brassica napus

“…The last gene from the list, At4g01010, encodes a cyclic nucleotide-gated channel, AtCNGC13. These calmodulin-binding channels have a plethora of functions in plants, from transport of potassium and other monovalent cations, to disease response signaling, to thermal sensing (Mäser et al, 2001;Ali et al, 2007;Finka et al, 2012). AtCNGC13 has not been characterized so far; however, reduced expression of its closest paralog, AtCNGC10, resulted in many developmental and growth defects, such as early flowering, starch accumulation, and growth retardation (Borsics et al, 2007).…”

Membrane Proteomic Analysis of Arabidopsis thaliana Using Alternative Solubilization Techniques

“…The Arabidopsis genome also contains six K + efflux antiporters (KEAs), which belong to monovalent cation: proton antiporter family 2 (CPA2 family), 38 whose role is to provide a means for the acidification of the cytosol as a defense to toxic electrophiles. 46 We identified two KEAs that are integral membrane proteins and members of the CPA2 family (Tables 1 and 3).…”

“…Approximately 5% of the Arabidopsis genome encodes membrane transport proteins. 38 These proteins can be categorized into several classes, which include the major intrinsic proteins (MIPs) that facilitate the passive transport of small polar molecules across membranes. 39 In Arabidopsis, there are 13 plasma membrane intrinsic proteins (PIPs) and 10 tonoplast intrinsic proteins (TIPs), both members of the MIP family.…”

Lesion mimic mutants

“…On the other hand, AtCNGC11 and 12, which are closest related to each other, belong to group I. 50 Several studies have shown that Arabidopsis CNGCs can function as non selective cation channels like their counterparts in animals. For examples, AtCNGC2 has been shown by patch clamp and yeast complementation analysis to be an inward rectifying Ca 2+ and K + channel.…”

“…CNGCs are a relatively uncharacterized family of ion channels comprising of 20 members. 50,51 AtCNGC2 and 4 are the sole members of Group IVB, which is the most divergent group among the 20 member family of CNGCs. On the other hand, AtCNGC11 and 12, which are closest related to each other, belong to group I.…”