INTERMEDIATE-SIZED FILAMENTS IN RAT KANGAROO PTK2 CELLS .2. STRUCTURE AND COMPOSITION OF ISOLATED FILAMENTS

Google Scholar
  • 1 January 1978
    • journal article
    • research article
    • Vol. 17  (2) , 392-411
Abstract
Cultured cells of the rat kangaroo kidney cell line PtK2 grown on plastic or glass surfaces were lysed and extracted with combinations of low and high salt buffers and the non-ionic detergent Triton X-100. The cytoskeletal preparations obtained showed an enrichment of 6-11 nm thick filaments. The arrays of these filaments were examined by various light microscopy and EM techniques, including ultrathin sectioning, whole mount transmission EM, negative staining and indirect immunofluorescence microscopy. In addition, 6-11 nm filaments isolated from these cells with similar extraction procedures and centrifugation techniques were examined by EM. The arrays of these isolated intermediate-sized filaments, their ultrastructure and their specific decoration by certain antibodies present in normal rabbit sera and by guinea pig antibodies against purified bovine prekeratin was demonstrated. When preparations enriched in these intermediate-sized filaments were examined by SDS[sodium dodecyl sulfate]-polyacrylamide gel electrophoresis a corresponding enrichment of 3 polypeptide bands with apparent MW of about 45,000, 52,000 and 58,000 (the latter component sometimes appears split into 2 bands) was observed, besides some residual actin and a few high MW bands. The morphology of the isolated filaments, their immunological reaction with antibodies decorating prekeratin-containing structures and the sizes of their constitutive polypeptides suggested that these filaments were closely related to prekeratin-containing filaments observed in a variety of epithelial cells.

This publication has 22 references indexed in Scilit: