This family represents the Plasmodium falciparum chloroquine resistance transporter (CRT) and homologous proteins. CRT regulates other transporters, like Na-H antiporter or nonselective cation transporters [1]. The Arabidopsis homologues are involved in thiol transport from the plastid to the cytosol, playing a significant role in regulating GSH levels and the redox potential of the cytosol [2]. Homologues from Dictyostelium discoideum are also included in this family [3].

1: Evidence for activation of endogenous transporters in Xenopus laevis oocytes expressing the Plasmodium falciparum chloroquine resistance transporter, PfCRT. Nessler S, Friedrich O, Bakouh N, Fink RH, Sanchez CP, Planelles G, Lanzer M; J Biol Chem. 2004;279:39438-39446. PMID:15258157

2: Plant homologs of the Plasmodium falciparum chloroquine-resistance transporter, PfCRT, are required for glutathione homeostasis and stress responses. Maughan SC, Pasternak M, Cairns N, Kiddle G, Brach T, Jarvis R, Haas F, Nieuwland J, Lim B, Muller C, Salcedo-Sora E, Kruse C, Orsel M, Hell R, Miller AJ, Bray P, Foyer CH, Murray JA, Meyer AJ, Cobbett CS; Proc Natl Acad Sci U S A. 2010;107:2331-2336. PMID:20080670

3: Dictyostelium discoideum expresses a malaria chloroquine resistance mechanism upon transfection with mutant, but not wild-type, Plasmodium falciparum transporter PfCRT. Naude B, Brzostowski JA, Kimmel AR, Wellems TE; J Biol Chem. 2005;280:25596-25603. PMID:15883156