Biochemical and functional characterization of a mitochondrial citrate carrier in Arabidopsis thaliana. Issue 9 (15th May 2020)

• Record Type: Journal Article
• Authors: Brito, Danielle S.; Agrimi, Gennaro; Charton, Lennart; Brilhaus, Dominik; Bitetto, Maria Gabriella; Lana-Costa, Jaciara; Messina, Eugenia; Nascimento, Carolina P.; Feitosa-Araújo, Elias; Pires, Marcel Viana; Pérez-Díaz, Jorge Luis; Obata, Toshihiro; Porcelli, Vito; Palmieri, Luigi; Araújo, Wagner L.; Weber, Andreas P.M.; Linka, Nicole; Fernie, Alisdair R.; Palmieri, Ferdinando; Nunes-Nesi, Adriano
• Is Part Of: Biochemical journal. Volume 477:Issue 9(2020)
• Page Start: 1759
• Page End: 1777
• Publication Date: 2020-05-15
• Subjects: Arabidopsis thaliana -- citrate -- isocitrat -- mitochondrial carrier -- succinate/fumarate carrier; Biochemistry -- Periodicals; 572
• DOI: 10.1042/BCJ20190785
• Languages: English
• ISSNs: 0264-6021

Abstract

Abstract : A homolog of the mitochondrial succinate/fumarate carrier from yeast (Sfc1p) has been found in the Arabidopsis genome, named At SFC1. The At SFC1 gene was expressed in Escherichia coli, and the gene product was purified and reconstituted in liposomes. Its transport properties and kinetic parameters demonstrated that At SFC1 transports citrate, isocitrate and aconitate and, to a lesser extent, succinate and fumarate. This carrier catalyzes a fast counter-exchange transport as well as a low uniport of substrates, exhibits a higher transport affinity for tricarboxylates than dicarboxylates, and is inhibited by pyridoxal 5′-phosphate and other inhibitors of mitochondrial carriers to various degrees. Gene expression analysis indicated that the At SFC1 transcript is mainly present in heterotrophic tissues, and fusion with a green-fluorescent protein localized At SFC1 to the mitochondria. Furthermore, 35S- AtSFC1 antisense lines were generated and characterized at metabolic and physiological levels in different organs and at various developmental stages. Lower expression of At SFC1 reduced seed germination and impaired radicle growth, a phenotype that was related to reduced respiration rate. These findings demonstrate that At SFC1 might be involved in storage oil mobilization at the early stages of seedling growth and in nitrogen assimilation in root tissue by catalyzing citrate/isocitrate or citrate/succinate exchanges.