title: Morphogenetic and molecular analyses of cyst wall components in the ciliated protozoan Colpoda cucullus Nag-1.
abstract: The cyst wall of the resting cyst of the ciliated protozoan Colpoda cucullus (Nag-1 strain) is composed of several layers of endocyst, a single layer of ectocyst associated with a mucous layer and lepidosomes composed of a fibrous or crystal-like structure. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis showed that the ectocyst associated with lepidosomes and mucous materials contained proteins corresponding to 27, 31, 45 kDa and smear bands ranging from 50 to 60 kDa. Liquid chromatography-tandem mass spectrometry of these proteins revealed that the 45-kDa protein (p45) was elongation factor Tu (EF-Tu). Immunofluorescence microscopy with an anti-EF-Tu polyclonal antibody showed that Colpoda EF-Tu (p45) was localized in the lepidosomes. The lepidosomes were stained vividly with Congo red, which is bound to the stacked β-sheets of amyloid protofibrils. In the presence of puromycin, no cyst wall components including lepidosomes were formed, indicating that cyst wall formation requires synthesis of proteins including EF-Tu. Electron microscopy of encysting cells implied that vesicles which were presumably budded from endoplasmic reticula possibly fuse with a lepidosome-precursor vacuole containing electron-dense fine particles or fibrous structures, and followed by the subsequent fusion with other electron-lucent granules.
authors: Department of Biological Science, Faculty of Science, Kochi University, Kochi 780-8520, Japan.
authors: Ryoji
authors: R
authors: Funadani
authors: Department of Biological Science, Faculty of Science, Kochi University, Kochi 780-8520, Japan.
authors: Yoichiro
authors: Y
authors: Sogame
authors: Department of Microbiology and Immunology, Shinshu University School of Medicine, 3-1-1 Asahi, Matsumoto, Nagano 390-8621, Japan.
authors: Katsuhiko
authors: K
authors: Kojima
authors: Department of Microbiology and Immunology, Shinshu University School of Medicine, 3-1-1 Asahi, Matsumoto, Nagano 390-8621, Japan.
authors: Toshikazu
authors: T
authors: Takeshita
authors: Department of Biological Science, Faculty of Science, Kochi University, Kochi 780-8520, Japan.
authors: Keisuke
authors: K
authors: Yamamoto
authors: Department of Biological Science, Faculty of Science, Kochi University, Kochi 780-8520, Japan.
authors: Tomoya
authors: T
authors: Tsujizono
authors: Division of Cancer Biology, Institute for Genetic Medicine, Hokkaido University, Sapporo, 060-0815 Japan.
authors: Futoshi
authors: F
authors: Suizu
authors: Department of Applied Biology, Kyoto Institute of Technology, Kyoto 606-8585, Japan.
authors: Seiji
authors: S
authors: Miyata
authors: The facility for Research Instruments, Kochi University, Nankoku, Kochi 783-8505, Japan.
authors: Ken-Ichi
authors: KI
authors: Yagyu
authors: Laboratory of Biochemistry, Faculty of Science, Kochi University, Kochi 780-8520, Japan.
authors: Tomohiko
authors: T
authors: Suzuki
authors: Department of Biological Science, Faculty of Science, Kochi University, Kochi 780-8520, Japan.
authors: Mikihiko
authors: M
authors: Arikawa
authors: Department of Biological Science, Faculty of Science, Kochi University, Kochi 780-8520, Japan tmatsuok@kochi-u.ac.jp.
authors: Tatsuomi
authors: T
authors: Matsuoka
keywords: 18S rRNA; Colpoda cucullus Nag-1; cyst wall proteins; encystment; lepidosome