Arabidopsis Tic40 Expression in Tobacco Chloroplasts Results in Massive Proliferation of the Inner Envelope Membrane and Upregulation of Associated Proteins
- 5 December 2008
- journal article
- Published by Oxford University Press (OUP) in THE PLANT CELL ONLINE
- Vol. 20 (12), 3405-3417
- https://doi.org/10.1105/tpc.108.063172
Abstract
The chloroplast inner envelope membrane (IM) plays essential roles in lipid synthesis, metabolite transport, and cellular signaling in plants. We have targeted a model nucleus-encoded IM protein from Arabidopsis thaliana, pre-Tic40-His, by relocating its expression from the nucleus to the chloroplast genome. Pre-Tic40-His was properly targeted, processed, and inserted. It attained correct topology and was folded and assembled into a TIC complex, where it accounted for up to 15% of the total chloroplast protein. These results confirm the existence of a novel pathway for protein targeting to the IM. Tic40-His overexpression resulted in a massive proliferation of the IM (up to 19 layers in electron micrographs) without significant effects on plant growth or reproduction. Consistent with IM proliferation, the expression levels of other endogenous IM proteins (IEP37, PPT, Tic110) were significantly (10-fold) upregulated but those of outer envelope membrane (Toc159), stromal (hsp93, cpn60), or thylakoid (LHCP, OE23) proteins were not increased, suggesting retrograde signal transduction between chloroplast and nuclear genomes to increase lipid and protein components for accommodation of increased accumulation of Tic40. This study opens the door for understanding the regulation of membrane biogenesis within the organelle and the utilization of transgenic chloroplasts as bioreactors for hyperaccumulation of membrane proteins for biotechnological applications.Keywords
This publication has 46 references indexed in Scilit:
- Tic40 is important for reinsertion of proteins from the chloroplast stroma into the inner membraneThe Plant Journal, 2008
- A role for lipid trafficking in chloroplast biogenesisProgress in Lipid Research, 2008
- Effective Plague Vaccination via Oral Delivery of Plant Cells Expressing F1-V Antigens in ChloroplastsInfection and Immunity, 2008
- Chloroplast Vector Systems for Biotechnology ApplicationsPlant Physiology, 2007
- Chloroplast envelope membranes: a dynamic interface between plastids and the cytosolPhotosynthesis Research, 2007
- Field production and functional evaluation of chloroplast‐derived interferon‐α2bPlant Biotechnology Journal, 2007
- Transgene containment by maternal inheritance: Effective or elusive?Proceedings of the National Academy of Sciences of the United States of America, 2007
- Stimulation of transit-peptide release and ATP hydrolysis by a cochaperone during protein import into chloroplastsThe Journal of cell biology, 2006
- Reconstitution of protein targeting to the inner envelope membrane of chloroplastsThe Journal of cell biology, 2006
- Increased amounts of HMG-CoA reductase induce "karmellae": a proliferation of stacked membrane pairs surrounding the yeast nucleus.The Journal of cell biology, 1988