Phylogenetic and biochemical evidence supports the recruitment of an ADP-glucose translocator for the export of photosynthate during plastid endosymbiosis.
Mol Biol Evol
; 27(12): 2691-701, 2010 Dec.
Article
em En
| MEDLINE
| ID: mdl-20576760
ABSTRACT
The acquisition of photosynthesis by eukaryotic cells through enslavement of a cyanobacterium represents one of the most remarkable turning points in the history of life on Earth. In addition to endosymbiotic gene transfer, the acquisition of a protein import apparatus and the coordination of gene expression between host and endosymbiont genomes, the establishment of a metabolic connection was crucial for a functional endosymbiosis. It was previously hypothesized that the first metabolic connection between both partners of endosymbiosis was achieved through insertion of a host-derived metabolite transporter into the cyanobacterial plasma membrane. Reconstruction of starch metabolism in the common ancestor of photosynthetic eukaryotes suggested that adenosine diphosphoglucose (ADP-Glc), a bacterial-specific metabolite, was likely to be the photosynthate, which was exported from the early cyanobiont. However, extant plastid transporters that have evolved from host-derived endomembrane transporters do not transport ADP-Glc but simple phosphorylated sugars in exchange for orthophosphate. We now show that those eukaryotic nucleotide sugar transporters, which define the closest relatives to the common ancestor of extant plastid envelope carbon translocators, possess an innate ability for transporting ADP-Glc. Such an unexpected ability would have been required to establish plastid endosymbiosis.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Fotossíntese
/
Filogenia
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Simbiose
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Plastídeos
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Proteínas de Transporte de Nucleotídeos
Idioma:
En
Ano de publicação:
2010
Tipo de documento:
Article