AtToc90, a New GTP-Binding Component of the Arabidopsis Chloroplast Protein Import Machinery |
| |
Authors: | Hiltbrunner Andreas Grünig Kathrin Alvarez-Huerta Mayte Infanger Sibylle Bauer Jörg Kessler Felix |
| |
Institution: | 1.Albert-Ludwigs-Universit?t Freiburg, Institut für Biologie II/Botanik, Sch?nzlestrasse 1, D-79104, Freiburg, Germany ;2.Institut de Botanique, Laboratoire de Physiologie Végétale, Université de Neuchatel, Rue Emile-Argand 11, CH-2007, Neuchatel, Switzerland ;3.BASF Plant Science GmbH, D-67056, Ludwigshafen, Germany ; |
| |
Abstract: | 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. |
| |
Keywords: | Arabidopsis chloroplast GTPase protein import translocon |
本文献已被 PubMed SpringerLink 等数据库收录! |
|