Proteomic analysis of the Cyanophora paradoxa muroplast provides clues on early events in plastid endosymbiosis

• Published in: Planta Vol. 237; no. 2; pp. 637 - 651
• Main Authors: Facchinelli, Fabio, Pribil, Mathias, Oster, Ulrike, Ebert, Nina J., Bhattacharya, Debashish, Leister, Dario, Weber, Andreas P. M.
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer-Verlag 01.02.2013; Springer Nature B.V
• Subjects: Agriculture; Agrobacterium tumefaciens - genetics; Agrobacterium tumefaciens - metabolism; Biological Evolution; Biomedical and Life Sciences; Carbon - metabolism; Chloroplasts; Cloning, Molecular; Cyanophora; Cyanophora - genetics; Cyanophora - metabolism; Cytosol - metabolism; Ecology; Eukaryotic cells; Evolution; Forestry; Genomes; Life Sciences; Nicotiana - genetics; Nicotiana - metabolism; Original Article; Phosphate Transport Proteins - metabolism; Phosphates; Plant Proteins - genetics; Plant Proteins - metabolism; Plant Sciences; Plants; Plastids; Plastids - genetics; Plastids - metabolism; Protein Transport; Proteins; Proteome - analysis; Proteomics; Proteomics - methods; Protoplasts - cytology; Protoplasts - metabolism; Symbiosis; Tandem Mass Spectrometry; Transformation, Genetic; Transporters; Evolution; Plastid; Endosymbiosis; Proteomics
• ISSN: 0032-0935; 1432-2048
• DOI: 10.1007/s00425-012-1819-3

Glaucophytes represent the first lineage of photosynthetic eukaryotes of primary endosymbiotic origin that diverged after plastid establishment. The muroplast of Cyanophora paradoxa represents a primitive plastid that resembles its cyanobacterial ancestor in pigment composition and the presence of a peptidoglycan wall. To attain insights into the evolutionary history of cyanobiont integration and plastid development, it would thus be highly desirable to obtain knowledge on the composition of the glaucophyte plastid proteome. Here, we provide the first proteomic analysis of the muroplast of C. paradoxa. Mass spectrometric analysis of the muroplast proteome identified 510 proteins with high confidence. The protein repertoire of the muroplast revealed novel paths for reduced carbon flow and export to the cytosol through a sugar phosphate transporter of chlamydial origin. We propose that C. paradoxa possesses a primordial plastid mirroring the situation in the early protoalga.