Different lumen-targeting pathways for nuclear-encoded versus cyanobacterial/plastid-encoded Hcf136 proteins.
FEBS Lett
; 467(1): 97-100, 2000 Feb 04.
Article
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| MEDLINE
| ID: mdl-10664464
ABSTRACT
Lumenal proteins are transported across the thylakoid membrane by two very different pathways Sec-dependent or twin-arginine translocase (Tat)-dependent, where the substrate protein can be transported in a folded state. We present the first evidence that a given protein can be targeted by different pathways in different organisms. Arabidopsis Hcf136 is targeted exclusively by the Tat pathway in pea chloroplasts and no Sec-dependent transport is evident even when the twin-arginine is replaced by twin-lysine. However, twin-arginine motifs are absent from the presequences of Hcf136 proteins encoded by plastid or cyanobacterial genomes, strongly implying translocation by another pathway (presumably Sec). We suggest that the Hcf136 protein was transferred to the Tat pathway when the gene became incorporated into the nuclear genome, possibly due to the tighter folding associated with the more involved, post-translational targeting pathway.
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Banco de datos:
MEDLINE
Asunto principal:
Proteínas de Transporte de Membrana
/
Proteínas Bacterianas
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Núcleo Celular
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Cianobacterias
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Plastidios
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Pisum sativum
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Tilacoides
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Proteínas de Escherichia coli
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Proteínas de Arabidopsis
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Proteínas de la Membrana
Idioma:
En
Año:
2000
Tipo del documento:
Article