title: The global phosphoproteome of Chlamydomonas reinhardtii reveals complex organellar phosphorylation in the flagella and thylakoid membrane.
abstract: Chlamydomonas reinhardtii is the most intensively-studied and well-developed model for investigation of a wide-range of microalgal processes ranging from basic development through understanding triacylglycerol production. Although proteomic technologies permit interrogation of these processes at the protein level and efforts to date indicate phosphorylation-based regulation of proteins in C. reinhardtii is essential for its underlying biology, characterization of the C. reinhardtii phosphoproteome has been limited. Herein, we report the richest exploration of the C. reinhardtii proteome to date. Complementary enrichment strategies were used to detect 4588 phosphoproteins distributed among every cellular component in C. reinhardtii. Additionally, we report 18,160 unique phosphopeptides at <1% false discovery rate, which comprise 15,862 unique phosphosites - 98% of which are novel. Given that an estimated 30% of proteins in a eukaryotic cell are subject to phosphorylation, we report the majority of the phosphoproteome (23%) of C. reinhardtii. Proteins in key biological pathways were phosphorylated, including photosynthesis, pigment production, carbon assimilation, glycolysis, and protein and carbohydrate metabolism, and it is noteworthy that hyperphosphorylation was observed in flagellar proteins. This rich data set is available via ProteomeXchange (ID: PXD000783) and will significantly enhance understanding of a range of regulatory mechanisms controlling a variety of cellular process and will serve as a critical resource for the microalgal community.
authors.affiliation: From the ‡Donald Danforth Plant Science Center, 975 North Warson Road, St Louis, Missouri 63132; §National Center of Biomedical Analysis, 27 Taiping Road, Beijing, 100850, China;
authors.forename: Hongxia
authors.initials: H
authors.lastname: Wang
authors.affiliation: From the ‡Donald Danforth Plant Science Center, 975 North Warson Road, St Louis, Missouri 63132; ¶Sigma-Aldrich, 2909 Laclede Ave., St. Louis, Missouri 63103;
authors.forename: Brian
authors.initials: B
authors.lastname: Gau
authors.affiliation: ‖Department of Chemistry, University of North Carolina at Chapel Hill, 125 South Road, Chapel Hill, North Carolina 27599;
authors.forename: William O
authors.initials: WO
authors.lastname: Slade
authors.affiliation: **Department of Plant Biology, Michigan State University, 612 Wilson Road, East Lansing, Missouri 48824.
authors.forename: Matthew
authors.initials: M
authors.lastname: Juergens
authors.affiliation: §National Center of Biomedical Analysis, 27 Taiping Road, Beijing, 100850, China;
authors.forename: Ping
authors.initials: P
authors.lastname: Li
authors.affiliation: From the ‡Donald Danforth Plant Science Center, 975 North Warson Road, St Louis, Missouri 63132; ‖Department of Chemistry, University of North Carolina at Chapel Hill, 125 South Road, Chapel Hill, North Carolina 27599; lmhicks@unc.edu.
authors.forename: Leslie M
authors.initials: LM
authors.lastname: Hicks
mesh_terms: D020418:Algal Proteins / Q000378:metabolism*; D016825:Chlamydomonas reinhardtii / Q000378:metabolism*; D002853:Chromatography, Liquid; D005407:Flagella / Q000378:metabolism*; D010750:Phosphoproteins / Q000378:metabolism*; D010766:Phosphorylation; D011108:Polymers; D040901:Proteomics; D053719:Tandem Mass Spectrometry; D020524:Thylakoids / Q000378:metabolism*; D014025:Titanium
chemical_list: D020418:Algal Proteins; D010750:Phosphoproteins; D011108:Polymers; C009495:titanium dioxide; D014025:Titanium