The Tic40 translocon components exhibit preferential interactions with different forms of the Oee1 plastid protein precursor
Kenton Ko, Susitna Banerjee, Jennette Innes, Darcie Taylor and Zdenka Ko
Functional Plant Biology
31(3) 285 - 294
Published: 15 April 2004
The transport of proteins across the plastid envelope involves a host of proteinaceous components that attend to varying structural needs of the process. This study focuses on interactions between two select forms (designated Tic40 and Toc36) of the Tic40-related components and different structural versions of the Oee1 precursor to dissect the components' mode of operation. Interaction profiling revealed several features pertaining to how Tic40-related components might work during the transport process. The main operational features revealed are: (1) Tic40 interacts preferentially with Oee1 precursors containing only the plastid-targeting domain, (2) Toc36 interacts preferentially with Oee1 precursors containing both plastid- and thylakoid lumen-targeting domains, (3) carboxyl truncations to either the entire Oee1 precursor or Toc36 affect interactions negatively, and (4) the general reduction of Tic40-related protein levels in transgenic plants appears to exert a greater negative impact on endogenous Oee1 levels than the other proteins assessed, a trend that corroborates the findings of the protein interaction experiments. Keywords: plastid translocon, precursor protein interactions, targeting domains, transport.
Full text doi:10.1071/FP03195
© CSIRO 2004