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AtToc90, a new GTP-binding component of the Arabidopsis chloroplast protein import machinery
Auteur(s)
Hiltbrunner, Andreas
Grunig, Kathrin
Alvarez-Huerta, Mayte
Infanger, Sibylle
Bauer, Jörg
Date de parution
2004
In
Plant Molecular Biology
Vol.
3
No
54
De la page
427
A la page
440
Mots-clés
Résumé
AtToc159 is a GTP-binding chloroplast protein import receptor. In vivo, atToc159 is required for massive accumulation of photosynthetic proteins during chloroplast biogenesis. Yet, in mutants lacking atToc159 photosynthetic proteins still accumulate, but at strongly reduced levels whereas non-photosynthetic proteins are imported normally: This suggests a role for the homologues of atToc159 (atToc132, - 120 and - 90). Here, we show that atToc90 supports accumulation of photosynthetic proteins in plastids, but is not required for import of several constitutive proteins. Part of atToc90 associates with the chloroplast surface in vivo and with the Toc-complex core components (atToc75 and atToc33) in vitro suggesting a function in chloroplast protein import similar to that of atToc159. As both proteins specifically contribute to the accumulation of photosynthetic proteins in chloroplasts they may be components of the same import pathway.
Identifiants
Type de publication
journal article
