PIC1, an ancient permease in Arabidopsis chloroplasts, mediates iron transport
| Autor: | Katrin Philippar, Gerhard Wanner, Nicolaus von Wirén, Anderson R. Meda, Daniela Duy, Jürgen Soll |
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| Rok vydání: | 2007 |
| Předmět: |
Chloroplasts
Iron Tic complex Molecular Sequence Data Arabidopsis Plant Science Photosynthesis Cytosol Gene Expression Regulation Plant Yeasts Arabidopsis thaliana Homeostasis Amino Acid Sequence Plastid Cation Transport Proteins Alleles Research Articles biology Base Sequence Sequence Homology Amino Acid Permease Arabidopsis Proteins Gene Expression Profiling Synechocystis food and beverages Membrane Transport Proteins Cell Biology biology.organism_classification Chloroplast Ferritin Plant Leaves Protein Transport Biochemistry biology.protein |
| Zdroj: | The Plant cell. 19(3) |
| ISSN: | 1040-4651 |
| Popis: | In chloroplasts, the transition metals iron and copper play an essential role in photosynthetic electron transport and act as cofactors for superoxide dismutases. Iron is essential for chlorophyll biosynthesis, and ferritin clusters in plastids store iron during germination, development, and iron stress. Thus, plastidic homeostasis of transition metals, in particular of iron, is crucial for chloroplast as well as plant development. However, very little is known about iron uptake by chloroplasts. Arabidopsis thaliana PERMEASE IN CHLOROPLASTS1 (PIC1), identified in a screen for metal transporters in plastids, contains four predicted α-helices, is targeted to the inner envelope, and displays homology with cyanobacterial permease-like proteins. Knockout mutants of PIC1 grew only heterotrophically and were characterized by a chlorotic and dwarfish phenotype reminiscent of iron-deficient plants. Ultrastructural analysis of plastids revealed severely impaired chloroplast development and a striking increase in ferritin clusters. Besides upregulation of ferritin, pic1 mutants showed differential regulation of genes and proteins related to iron stress or transport, photosynthesis, and Fe-S cluster biogenesis. Furthermore, PIC1 and its cyanobacterial homolog mediated iron accumulation in an iron uptake–defective yeast mutant. These observations suggest that PIC1 functions in iron transport across the inner envelope of chloroplasts and hence in cellular metal homeostasis. |
| Databáze: | OpenAIRE |
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