title: Proteomic analysis of the Cyanophora paradoxa muroplast provides clues on early events in plastid endosymbiosis.
abstract: 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.
authors.affiliation: Institute of Plant Biochemistry, Cluster of Excellence on Plant Sciences, Heinrich-Heine-University, Universitätsstraße 1, Düsseldorf, Germany.
authors.forename: Fabio
authors.initials: F
authors.lastname: Facchinelli
authors.forename: Mathias
authors.initials: M
authors.lastname: Pribil
authors.forename: Ulrike
authors.initials: U
authors.lastname: Oster
authors.forename: Nina J
authors.initials: NJ
authors.lastname: Ebert
authors.forename: Debashish
authors.initials: D
authors.lastname: Bhattacharya
authors.forename: Dario
authors.initials: D
authors.lastname: Leister
authors.forename: Andreas P M
authors.initials: AP
authors.lastname: Weber
mesh_terms: D016960:Agrobacterium tumefaciens / Q000235:genetics / Q000378:metabolism; D005075:Biological Evolution; D002244:Carbon / Q000378:metabolism; D003001:Cloning, Molecular; D044424:Cyanophora / Q000235:genetics / Q000378:metabolism*; D003600:Cytosol / Q000378:metabolism; D028061:Phosphate Transport Proteins / Q000378:metabolism; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D018087:Plastids / Q000235:genetics / Q000378:metabolism*; D021381:Protein Transport; D020543:Proteome / Q000032:analysis*; D040901:Proteomics / Q000379:methods; D011523:Protoplasts / Q000166:cytology / Q000378:metabolism; D013559:Symbiosis; D053719:Tandem Mass Spectrometry; D014026:Nicotiana / Q000235:genetics / Q000378:metabolism; D014170:Transformation, Genetic
chemical_list: D028061:Phosphate Transport Proteins; D010940:Plant Proteins; D020543:Proteome; D002244:Carbon