pH sensitivity of the GTPase Toc33 as a regulatory circuit for protein translocation into chloroplasts

Bionda, Tihana, Koenig, Patrick, Oreb, Mislav, Tews, Ivo and Schleiff, Enrico (2008) pH sensitivity of the GTPase Toc33 as a regulatory circuit for protein translocation into chloroplasts. Plant and Cell Physiology, 49, (12), 1917-1921. (doi:10.1093/pcp/pcn171). (PMID:19001421).


[img] PDF (Original Article) - Version of Record
Restricted to System admin

Download (163Kb) | Request a copy


The properties of membrane-embedded GTPases are investigated to understand translocation of preprotein across the outer envelope of chloroplasts. The homo- and heterodimerization events of the GTPases had been established previously. We show that the hydrolytic activity of the GTPase Toc33 is pH insensitive in the homodimeric conformation but has a bell-shaped pH optimum in the monomeric conformation. Further, Toc33 GTPase homodimerization and protein translocation into chloroplasts are pH sensitive as well. pH sensitivity might serve to regulate translocation; alternatively, the documented pH sensitivity might reflect a mechanistic requirement for GTPase silencing during translocation as the GTPase switches between homo- and heterodimeric conformations.

Item Type: Article
Digital Object Identifier (DOI): doi:10.1093/pcp/pcn171
ISSNs: 0032-0781 (print)
1471-9053 (electronic)
Keywords: arabidopsis thaliana and Pisum sativum, imerization, gtpase, ph sensitivity, protein translocation, toc
Subjects: Q Science > QP Physiology
Divisions : Faculty of Natural and Environmental Sciences > Biological Sciences
ePrint ID: 200515
Accepted Date and Publication Date:
December 2008Published
10 November 2008Made publicly available
Date Deposited: 26 Oct 2011 10:40
Last Modified: 31 Mar 2016 13:45

Actions (login required)

View Item View Item

Downloads from ePrints over the past year. Other digital versions may also be available to download e.g. from the publisher's website.

View more statistics