CAX1, an H+/Ca2+ antiporter from Arabidopsis.

Abstract

Reestablishment of the resting state after stimulus-coupled elevations of cytosolic-free Ca2+ requires the rapid removal of Ca2+ from the cytosol of plant cells. Here we describe the isolation of two genes, CAXI and CAX2, from Arabidopsis thaliana that suppress a mutant of Saccharomyces cerevisiae that has a defect in vacuolar Ca2+ accumulation. (20). RNA was purified and analyzed as described (21). Degenerate PCR was performed using tomato genomic DNA as template. The sequences of the CAX primers were 5'-GCTTTTATCAGTRYCATCTTGCTTCC-3', where R = A or G and Y = C or T, and 5'-GTCCATCTKTTGMC-CCATCCAWCCAAT-3', where K = T or G, M = C or A, and W = A or T. Amplification was for 50 cycles using the following thermal profile: 94°C for 1 min, 55°C for 1.5 min, 72°C for 1 min, followed by a final 5 min of extension at 72°C. The PCR product was isolated, cloned into pGEM-T vector (Promega) and sequenced.

A calmodulin‐stimulated Ca2+‐ATPase from plant vacuolar membranes with a putative regulatory domain at its N‐terminus1

“…The presence of Ca 2 + -ATPases in the vacuolar membrane has been reported previously [3,23,24]. This would imply the presence of at least two Ca2+ -transport systems in this membrane: one is the BCAI Ca2+ -ATPase, and the other is a Ca 2 +/H+ antiporter [25]. Similarly, yeast vacuolar membranes contain a Ca 2 +-ATPase (Pmc1p) as well as a Ca 2 +/H+ antiporter (Vcxlp), both of which are characterized at the molecular level [26,27].…”

CAX‐ing a wide net: Cation/H+ transporters in metal remediation and abiotic stress signalling

“…1996, 2000; Ueoka‐Nakanishi et al . 1999), recent studies are beginning to implicate CAXs in a range of cellular and physiological processes, including stomatal function via cellular pH regulation, phosphate starvation signalling and hypoxia.…”

“…1996), many studies have examined the biochemical, genetic and physiological functions of these transport proteins, principally for isoforms from Arabidopsis thaliana and rice ( Oryza sativa ), and often by using the approaches of yeast heterologous expression and T‐DNA insertion mutagenesis (for review see Shigaki & Hirschi 2006; Manohar et al . 2011a).…”

AtCCX1 transports Na+ and K+ in Pitch pastoris

“…(Hirschi et al, 1996;Hirschi, 1999;Pittman et al, 2004;Mei et al, 2007). However, most members of CCXs have not yet to be identified and their transport properties are needed to complete urgently.…”