Metabolic adaptation in transplastomic plants massively accumulating recombinant proteins

• Published in: PloS one Vol. 6; no. 9; p. e25289
• Main Authors: Bally, Julia, Job, Claudette, Belghazi, Maya, Job, Dominique
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 22.09.2011; Public Library of Science (PLoS)
• Subjects: Accumulation; Aequorea victoria; Arabidopsis thaliana; Bioassays; Biological assays; Biology; Calvin cycle; Carbon dioxide; Chemical bonds; Chloroplasts; Chloroplasts - genetics; Chloroplasts - metabolism; Coding; Dioxygenase; Ecology, environment; Enzymes; Fitness; Fluorescence; Food science; Genetic transformation; Glycine; Green fluorescent protein; Green Fluorescent Proteins - genetics; Green Fluorescent Proteins - metabolism; Kinases; Laboratories; Life Sciences; Metabolism; Microbiology and Parasitology; Mitochondria; Molecular biology; Molecular weight; Nicotiana - genetics; Nicotiana - metabolism; Nutrition; Oxygenase; Plant cells; Plant Proteins - genetics; Plant Proteins - metabolism; Plants, Genetically Modified - genetics; Plants, Genetically Modified - metabolism; Plastids - genetics; Plastids - metabolism; Proteins; Proteomics; Pseudomonas fluorescens; Pyruvic acid; Recombinant proteins; Recombinant Proteins - genetics; Recombinant Proteins - metabolism; Ribulose-bisphosphate carboxylase; Ribulose-Bisphosphate Carboxylase - genetics; Ribulose-Bisphosphate Carboxylase - metabolism; Symbiosis; Tobacco; Transformation; Transgenic plants
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0025289

Recombinant chloroplasts are endowed with an astonishing capacity to accumulate foreign proteins. However, knowledge about the impact on resident proteins of such high levels of recombinant protein accumulation is lacking. Here we used proteomics to characterize tobacco (Nicotiana tabacum) plastid transformants massively accumulating a p-hydroxyphenyl pyruvate dioxygenase (HPPD) or a green fluorescent protein (GFP). While under the conditions used no obvious modifications in plant phenotype could be observed, these proteins accumulated to even higher levels than ribulose 1,5-bisphosphate carboxylase/oxygenase (Rubisco), the most abundant protein on the planet. This accumulation occurred at the expense of a limited number of leaf proteins including Rubisco. In particular, enzymes involved in CO(2) metabolism such as nuclear-encoded plastidial Calvin cycle enzymes and mitochondrial glycine decarboxylase were found to adjust their accumulation level to these novel physiological conditions. The results document how protein synthetic capacity is limited in plant cells. They may provide new avenues to evaluate possible bottlenecks in recombinant protein technology and to maintain plant fitness in future studies aiming at producing recombinant proteins of interest through chloroplast transformation.