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Biochemical Study of Proteins of Cortical Cytoskeleton in the Ciliate Isotricha prostoma 1
Author(s) -
Vigues Bernard,
Metenier G.,
Grolière C. A.,
Grain J.,
Sénaud J.
Publication year - 1985
Publication title -
the journal of protozoology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.067
H-Index - 77
eISSN - 1550-7408
pISSN - 0022-3921
DOI - 10.1111/j.1550-7408.1985.tb03010.x
Subject(s) - heavy meromyosin , cytoskeleton , endoplasmic reticulum , actin , polyacrylamide gel electrophoresis , tubulin , ciliate , microtubule , molecular mass , chemistry , biology , biophysics , gel electrophoresis , polyacrylamide , incubation , biochemistry , microbiology and biotechnology , cell , genetics , enzyme
In Isotricha prostoma , proteins of isolated cortices retaining the ecto‐endoplasmic fibrillar boundary (EEB) have been separated by one‐ and two‐dimensional gel electrophoresis. In addition to that of tubulin, four main bands corresponding to polypeptide molecular weights of 185, 35, 23, and 22 kd have been observed on 9% SDS‐polyacrylamide gels. Supernumerary major bands within a low molecular weight range (11‐19 kd) are evident after separation on 7.5‐15% polyacrylamide gradient gels. Two‐dimensional analysis discloses ‐ 150 polypeptide spots, most of them focusing within an acidic pl range 4.6‐5.3. The cortical fibrillar structures are still distinguishable after incubation in solutions containing 1.0 M K. Cl (12 h) or 0.6 M Kl (8 h). A prolonged KI treatment (52 h), however, results in the removal of EEB filaments (˜4 nm in diameter) and of a large part of the kinetid elements, so that the insoluble material is mainly represented by a reticulum of 6‐nm filaments interconnecting the proximal regions of kinetosomes. Two proteins with MW of 58 and 63 kd appear to be constituents of this kinetosome‐associated filamentous reticulum. Some of the cortical proteins with MW ≤23 kd are the most likely candidates for components of EEB filaments. The absence of decoration with heavy meromyosin confirms that actin is not a major component of Isotricha cortical cytoskeleton.