title: Fate of the 63-kDa periplasmic protein of the infectious form of the endonuclear symbiotic bacterium Holospora obtusa during the infection process.
abstract: Holospora obtusa is a macronucleus-specific endosymbiotic bacterium of the ciliate Paramecium caudatum. We report the secretion of a 63-kDa periplasmic protein of an infectious form of the bacterium into the macronucleus of its host. Indirect immunofluorescence microscopy with five monoclonal antibodies against the 63-kDa protein demonstrated that, soon after the bacterial invasion into the host macronucleus, the protein was detected in the infected macronucleus and that levels of the protein increased dramatically within one day of infection. The use of inhibitors for host and bacterial protein synthesis illustrated that, in early infection of H. obtusa, not only the pre-existing but also a newly synthesized 63-kDa protein was secreted into the host macronucleus. A partial amino acid sequence of the protein was determined, and a gene encoding the 63-kDa protein was cloned. The deduced amino acid sequence shows that this protein is a novel protein.
authors.affiliation: Department of Natural Science and Symbiosis, Graduate School of Science and Engineering, Yamaguchi University, Yamaguchi, Japan.
authors.forename: Fema
authors.initials: F
authors.lastname: Abamo
authors.forename: Hideo
authors.initials: H
authors.lastname: Dohra
authors.forename: Masahiro
authors.initials: M
authors.lastname: Fujishima
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D000907:Antibodies, Bacterial / Q000032:analysis; D000911:Antibodies, Monoclonal / Q000032:analysis; D001426:Bacterial Proteins / Q000032:analysis / Q000378:metabolism*; D003001:Cloning, Molecular; D042281:Holosporaceae / Q000166:cytology / Q000187:drug effects / Q000502:physiology*; D048648:Macronucleus / Q000382:microbiology*; D051379:Mice; D008807:Mice, Inbred BALB C; D008969:Molecular Sequence Data; D048488:Paramecium caudatum / Q000382:microbiology* / Q000502:physiology; D033903:Periplasmic Proteins / Q000032:analysis / Q000378:metabolism*; D011500:Protein Synthesis Inhibitors / Q000494:pharmacology; D020539:Sequence Analysis, Protein; D013559:Symbiosis
chemical_list: D000900:Anti-Bacterial Agents; D000907:Antibodies, Bacterial; D000911:Antibodies, Monoclonal; D001426:Bacterial Proteins; D033903:Periplasmic Proteins; D011500:Protein Synthesis Inhibitors