title: Proteomic profiling reveals compartment-specific, novel functions of ascidian sperm proteins.
abstract: In this study, we performed extensive proteomic analysis of sperm from the ascidian Ciona intestinalis. Sperm were fractionated into heads and flagella, followed by further separation into Triton X-100-soluble and -insoluble fractions. Proteins from each fraction and whole sperm were separated by isoelectric focusing using two different pH ranges, followed by SDS-PAGE at two different polyacrylamide concentrations. In total, 1,294 protein spots representing 304 non-redundant proteins were identified by mass spectrometry (MALDI-TOF). On comparison of the proteins in each fraction, we were able to identify the proteins specific to different sperm compartments. Further comparison with the testis proteome allowed the pairing of proteins with sperm-specific functions. Together with information on gene expression in developing embryos and adult tissues, these results provide insight into novel cellular and functional aspects of sperm proteins, such as distinct localization of actin isoforms, novel Ca(2+)-binding proteins in axonemes, localization of testis-specific serine/threonine kinase, and the presence of G-protein coupled signaling and ubiquitin pathway in sperm flagella.
authors.affiliation: Shimoda Marine Research Center, University of Tsukuba, Shimoda, Shizuoka, Japan.
authors.forename: Mia
authors.initials: M
authors.lastname: Nakachi
authors.forename: Ayako
authors.initials: A
authors.lastname: Nakajima
authors.forename: Mamoru
authors.initials: M
authors.lastname: Nomura
authors.forename: Kouki
authors.initials: K
authors.lastname: Yonezawa
authors.forename: Keisuke
authors.initials: K
authors.lastname: Ueno
authors.forename: Toshinori
authors.initials: T
authors.lastname: Endo
authors.forename: Kazuo
authors.initials: K
authors.lastname: Inaba
mesh_terms: D000199:Actins / Q000378:metabolism; D000818:Animals; D054468:Axoneme / Q000378:metabolism; D002938:Ciona intestinalis / Q000378:metabolism*; D015180:Electrophoresis, Gel, Two-Dimensional; D004591:Electrophoresis, Polyacrylamide Gel; D019204:GTP-Binding Proteins / Q000378:metabolism; D008297:Male; D017830:Octoxynol; D009928:Organ Specificity; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism; D020543:Proteome / Q000032:analysis / Q000378:metabolism*; D040901:Proteomics; D013077:Sperm Head / Q000737:chemistry / Q000378:metabolism*; D013082:Sperm Tail / Q000737:chemistry / Q000378:metabolism*; D025801:Ubiquitin / Q000378:metabolism
chemical_list: D000199:Actins; D020543:Proteome; D025801:Ubiquitin; D017830:Octoxynol; D017346:Protein Serine-Threonine Kinases; D019204:GTP-Binding Proteins