Studies of Tektin Filaments from Flagellar Microtubules by Immunoelectron Microscopy

SUMMARY Chemically resistant 2–3 nm filaments with a high α-helical content, isolated from sea-urchin sperm flagellar doublet microtubules, consist of proteins that have been named tektins. Polyclonal affinity-purified antibodies to tektins labelled sperm tails all along their lengths, as shown by indirect immunofluorescence microscopy, provided the specimens were not too well fixed. Results obtained for unfixed specimens studied by immunoelectron microscopy suggested the tektins are normally masked by tubulin. A monoclonal anti-tektin antibody labelled bare tektin filaments at longitudinal intervals of approximately 48 nm, which fits in well with the 96 nm longitudinal repeat of axonemes. We discuss a possible scheme for the regular interaction of tubulin monomers with an α-helical coiled coil.

[1]  G. Langevin,et al.  Structure and chemical composition of insoluble filamentous components of sperm flagellar microtubules. , 1982, Journal of cell science.

[2]  M. Potschka.  The structure of intermediate filaments. , 1986, Biophysical journal.

[3]  G. Olson,et al.  Arrangement of tubulin subunits and microtubule-associated proteins in the central-pair microtubule apparatus of squid (Loligo pealei) sperm flagella , 1981, The Journal of cell biology.

[4]  E. Mandelkow,et al.  Microtubule structure at low resolution by x-ray diffraction. , 1977, Proceedings of the National Academy of Sciences of the United States of America.

[5]  R. E. Stephens.  Differential protein synthesis and utilization during cilia formation in sea urchin embryos. , 1977, Developmental biology.

[6]  A. Mclachlan,et al.  Periodic charge distribution in the intermediate filament proteins desmin and vimentin. , 1982, Journal of molecular biology.

[7]  M. Raff,et al.  All classes of intermediate filaments share a common antigenic determinant defined by a monoclonal antibody , 1981, Cell.

[8]  R. Linck.  Flagellar doublet microtubules: fractionation of minor components and alpha-tubulin from specific regions of the A-tubule. , 1976, Journal of cell science.

[9]  G. Langevin,et al.  Reassembly of flagellar B (alpha beta) tubulin into singlet microtubules: consequences for cytoplasmic microtubule structure and assembly , 1981, The Journal of cell biology.

[10]  L. Amos,et al.  Localization of tektin filaments in microtubules of sea urchin sperm flagella by immunoelectron microscopy , 1985, The Journal of cell biology.

[11]  J. Bryan,et al.  Chemical heterogeneity of protofilaments forming the outer doublets from sea urchin flagella. , 1972, Experimental cell research.

[12]  A. Mclachlan,et al.  The 14-fold periodicity in α-tropomyosin and the interaction with actin , 1976 .

[13]  E. Fuchs,et al.  Unraveling the structure of the intermediate filaments , 1983, Cell.

[14]  J. Kilmartin,et al.  Rat monoclonal antitubulin antibodies derived by using a new nonsecreting rat cell line , 1982, The Journal of cell biology.