title: Protein phosphorylation in encystment-induced Colpoda cucullus: localization and identification of phosphoproteins.
abstract: In Colpoda cucullus, the morphogenetic transformation was preceded by an enhancement of the in vivo protein phosphorylation level. Immunofluorescence microscopy using antiphosphoserine antibody showed that these phosphorylated proteins were localized in the macronucleus and other cytoplasmic regions. Biotinylated Phos-tag/ECL assays of isolated macronuclei showed that a 33-kDa protein (p33) was localized within them. The p33 obtained from isolated macronuclei was tentatively identified as ribosomal P0 protein by LC-MS/MS analysis. In addition, among the encystment-specific phosphoproteins obtained by phosphate-affinity chromatography, the 29-, 31-, and 33-kDa proteins (p29, p31, and p33) were tentatively identified as ribosomal P0 protein, whereas the 24-kDa phosphoprotein (p24) was tentatively identified as ribosomal S5 protein.
authors.affiliation: Institute of Biological Science, Faculty of Science, Kochi University, Kochi, Japan.
authors.forename: Yoichiro
authors.initials: Y
authors.lastname: Sogame
authors.forename: Katsuhiko
authors.initials: K
authors.lastname: Kojima
authors.forename: Toshikazu
authors.initials: T
authors.lastname: Takeshita
authors.forename: Shigeki
authors.initials: S
authors.lastname: Fujiwara
authors.forename: Seiji
authors.initials: S
authors.lastname: Miyata
authors.forename: Eiji
authors.initials: E
authors.lastname: Kinoshita
authors.forename: Tatsuomi
authors.initials: T
authors.lastname: Matsuoka
mesh_terms: D000818:Animals; D002853:Chromatography, Liquid; D016798:Ciliophora / Q000254:growth & development / Q000378:metabolism* / Q000502:physiology* / Q000648:ultrastructure; D008856:Microscopy, Fluorescence; D010750:Phosphoproteins / Q000378:metabolism*; D010766:Phosphorylation; D015800:Protozoan Proteins / Q000378:metabolism*; D012269:Ribosomal Proteins / Q000378:metabolism; D033761:Spores, Protozoan / Q000378:metabolism / Q000502:physiology / Q000648:ultrastructure; D053719:Tandem Mass Spectrometry
chemical_list: D010750:Phosphoproteins; D015800:Protozoan Proteins; D012269:Ribosomal Proteins; C054675:ribosomal protein P0; C030831:ribosomal protein S5