Evolution of Plant P-Type ATPases

Abstract

Five organisms having completely sequenced genomes and belonging to all major branches of green plants (Viridiplantae) were analyzed with respect to their content of P-type ATPases encoding genes. These were the chlorophytes Ostreococcus tauri and Chlamydomonas reinhardtii, and the streptophytes Physcomitrella patens (a non-vascular moss), Selaginella moellendorffii (a primitive vascular plant), and Arabidopsis thaliana (a model flowering plant). Each organism contained sequences for all five subfamilies of P-type ATPases. Whereas Na+ and H+ pumps seem to mutually exclude each other in flowering plants and animals, they co-exist in chlorophytes, which show representatives for two kinds of Na+ pumps (P2C and P2D ATPases) as well as a primitive H+-ATPase. Both Na+ and H+ pumps also co-exist in the moss P. patens, which has a P2D Na+-ATPase. In contrast to the primitive H+-ATPases in chlorophytes and P. patens, the H+-ATPases from vascular plants all have a large C-terminal regulatory domain as well as a conserved Arg in transmembrane segment 5 that is predicted to function as part of a backflow protection mechanism. Together these features are predicted to enable H+ pumps in vascular plants to create large electrochemical gradients that can be modulated in response to diverse physiological cues. The complete inventory of P-type ATPases in the major branches of Viridiplantae is an important starting point for elucidating the evolution in plants of these important pumps.

Proton pump and plant cell elongation

“…It plays an important bioenergetics and regulatory function in plant cell physiology (Polevoi, 1986;Gaxiola, Palmgren, and Schumacher, 2007). The structure and evolution of the PM proton pump are well documented (Pedersen et al, 2007(Pedersen et al, , 2012. The protein consists of six transmembrane domains, two cytosolic loops and a long C-terminal domain (rev.…”

ACA12 is a deregulated isoform of plasma membrane Ca2+-ATPase of Arabidopsis thaliana

“…The genome of higher plants encodes several Ca 2+ -ATPases which group either with animal sarco-endoplasmic reticulum Ca 2+ -ATPase in the 2A subgroup of P-type ATPases (ECA, E R-type C a 2+ - A TPase) or with animal plasma membrane (PM) Ca 2+ -ATPase in the 2B subgroup (ACA, a uto-inhibited C a 2+ - A TPase). Arabidopsis ( Arabidopsis thaliana ) has four ECA and ten ACA genes, with most cells expressing multiple isoforms (Geisler et al 2000a; Sze et al 2000; Bonza and De Michelis 2011; Pedersen et al 2012). …”

“…In previously characterized members of the ACA subgroup, the N-terminus has been found to have an auto-inhibitory domain and a partially overlapping high affinity calmodulin (CaM) binding site (Geisler et al 2000a; Baxter et al 2003; Kabala and Klobus 2005; Boursiac and Harper 2007; Bonza and De Michelis 2011; Pedersen et al 2012); a second low affinity CaM-binding site has been recently identified just 8 aa downstream the first one in ACA8, one of the best characterized ACA isoform (Tidow et al 2012). In all ACA isoforms characterized so far, CaM-binding suppresses the auto-inhibitory action of the N-terminus, increasing V max and decreasing K 0.5 for free Ca 2+ .…”

Functional expression of an animal type-Na+-ATPase gene from a marine red seaweed Porphyra yezoensis increases salinity tolerance in rice plants

“…With its electroneutral function, a Na + / H + antiporter cannot perform Na + efflux under high pH conditions, whereas Na + /K + -ATPase and ENA ATPase are ΔpH-independent and thus they can mediate Na + efflux under alkaline pH conditions (Garciadeblas et al 2001;Rodríguez-Navarro and Benito 2010). Genome sequence information has revealed the loss of Na + -ATPase in vascular plants during evolution in fresh water environments (Graciadeblas et al 2001;Pedersen et al 2012), and the existence of Na + /K + -ATPase and/or ENA ATPase in eukaryotes living in highly alkaline and saline environments such as the sea was proposed.…”

“…Eukaryotes possess a P-type ATPase as a primary pump on the plasma membrane, which can play essential roles in the homeostasis of intracellular Na + concentrations (Palmgren and Nissen 2011;Pedersen et al 2012). There are three kinds of P-type ATPase related to Na + efflux across the plasma membrane; Na + /K + -ATPase in animal cells, H + -ATPase in plant and fungal cells and ENA ATPase found in bryophytes and protozoa.…”