tailieunhanh - Báo cáo khoa học: The mitochondrial protein frataxin is essential for heme biosynthesis in plants

Frataxin, a conserved mitochondrial protein implicated in cellular iron homeostasis, has been involved as the iron chaperone that delivers iron for the Fe–S cluster and heme biosynthesis. However, its role in iron metabo-lism remains unclear, especially in photosynthetic organisms. | IFEBS Journal The mitochondrial protein frataxin is essential for heme biosynthesis in plants It D _ Ifta l l 2 1 I 1 I 2 I I I 2 A I I A 3 I Maria V. Maliandi Maria V. Busi Valeria R. Turowski Laura Leaden Alejandro Araya and Diego F. Gomez-Casati2 1 Institute de Investigaciones Biotecnologicas-Instituto Tecnologico de Chascomus IIB-INTECH CONICET UNSAM Argentina 2 Centro de Estudios Fotosinteticos y Bioquimicos CEFOBI-CONICET Universidad Nacionalde Rosario Argentina 3 Microbiologie Cellulaire et Moleculaire et Pathogenicite UMR 5234 Centre Nationalde la Recherche Scientifique and Universite Victor Segalen-Bordeaux 2 France Keywords Arabidopsis catalase frataxin hemeproteins mitochondria Correspondence D. F. Gomez-Casati Centro de Estudios Fotosinteticos y Bioquimicos CEFOBI-CONICET Universidad Nacionalde Rosario Suipacha 531 2000 Rosario Argentina Fax 54 341 437 0044 Tel 54 341 437 1955 E-mail gomezcasati@ Received 21 July 2010 revised 15 October 2010 accepted 18 November 2010 doi Frataxin a conserved mitochondrial protein implicated in cellular iron homeostasis has been involved as the iron chaperone that delivers iron for the Fe-S cluster and heme biosynthesis. However its role in iron metabolism remains unclear especially in photosynthetic organisms. In previous work we found that frataxin deficiency in Arabidopsis results in decreased activity of the mitochondrial Fe-S proteins aconitase and succinate dehydrogenase despite the increased expression of the respective genes indicating an important role for Arabidopsis thaliana frataxin homolog AtFH . In this work we explore the hypothesis that AtFH can participate in heme formation in plants. For this purpose we used two Arabidopsis lines atfh-1 and as-AtFH with deficiency in the expression of AtFH. Both lines present alteration in several transcripts from the heme biosynthetic route with a decrease in total heme content and a deficiency in catalase activity