Skip to main content
NCBI home page
The Journal of Cell Biology logoLink to The Journal of Cell Biology
. 1984 Apr 1;98(4):1231–1237. doi: 10.1083/jcb.98.4.1231

Isolation and characterization of keratin-like proteins from cultured cells with fibroblastic morphology

PMCID: PMC2113247  PMID: 6201488

Abstract

Intermediate filaments (IF) isolated from a variety of cultured cells, conventionally described as fibroblasts, are composed predominantely of proteins of molecular weights of 54,000 and/or 55,000. Less than 15% of the protein found in native IF preparations from these cells is composed of three to four polypeptides of molecular weights 60,000- 70,000. We have investigated some biochemical and immunological properties of these proteins isolated from BHK-21 and mouse 3T3 cells. They are capable of forming paracrystals that exhibit a light/dark banding pattern when negatively stained with uranyl acetate. The dark bands are composed of longitudinally aligned approximately 2-nm-diam filaments. The center-to-center spacing between either dark or light bands is 37-40 nm. These dimensions are consistent with the secondary structure of IF polypeptides and suggest that the dark bands represent lateral alignment of alpha-helical coiled-coil domains. Immunoblotting, secondary structure, as well as amino acid composition data indicate that the 60,000-70,000-mol-wt paracrystal polypeptides are similar to keratin. Thus, polypeptides with biochemical and immunological properties of epidermal keratin are present in cells normally considered to be fibroblasts.

Full Text

The Full Text of this article is available as a PDF (864.7 KB).

Selected References

These references are in PubMed. This may not be the complete list of references from this article.

  1. Albrecht-Buehler G., Bushnell A. Reversible compression of cytoplasm. Exp Cell Res. 1982 Jul;140(1):173–189. doi: 10.1016/0014-4827(82)90168-9. [DOI] [PubMed] [Google Scholar]
  2. Franke W. W., Schmid E., Osborn M., Weber K. Different intermediate-sized filaments distinguished by immunofluorescence microscopy. Proc Natl Acad Sci U S A. 1978 Oct;75(10):5034–5038. doi: 10.1073/pnas.75.10.5034. [DOI] [PMC free article] [PubMed] [Google Scholar]
  3. Franke W. W., Weber K., Osborn M., Schmid E., Freudenstein C. Antibody to prekeratin. Decoration of tonofilament like arrays in various cells of epithelial character. Exp Cell Res. 1978 Oct 15;116(2):429–445. doi: 10.1016/0014-4827(78)90466-4. [DOI] [PubMed] [Google Scholar]
  4. Gard D. L., Bell P. B., Lazarides E. Coexistence of desmin and the fibroblastic intermediate filament subunit in muscle and nonmuscle cells: identification and comparative peptide analysis. Proc Natl Acad Sci U S A. 1979 Aug;76(8):3894–3898. doi: 10.1073/pnas.76.8.3894. [DOI] [PMC free article] [PubMed] [Google Scholar]
  5. Geisler N., Kaufmann E., Weber K. Proteinchemical characterization of three structurally distinct domains along the protofilament unit of desmin 10 nm filaments. Cell. 1982 Aug;30(1):277–286. doi: 10.1016/0092-8674(82)90033-2. [DOI] [PubMed] [Google Scholar]
  6. Gerace L., Blum A., Blobel G. Immunocytochemical localization of the major polypeptides of the nuclear pore complex-lamina fraction. Interphase and mitotic distribution. J Cell Biol. 1978 Nov;79(2 Pt 1):546–566. doi: 10.1083/jcb.79.2.546. [DOI] [PMC free article] [PubMed] [Google Scholar]
  7. Hanukoglu I., Fuchs E. The cDNA sequence of a human epidermal keratin: divergence of sequence but conservation of structure among intermediate filament proteins. Cell. 1982 Nov;31(1):243–252. doi: 10.1016/0092-8674(82)90424-x. [DOI] [PubMed] [Google Scholar]
  8. Henderson L. E., Oroszlan S., Konigsberg W. A micromethod for complete removal of dodecyl sulfate from proteins by ion-pair extraction. Anal Biochem. 1979 Feb;93(1):153–157. [PubMed] [Google Scholar]
  9. Jones J. C., Goldman A. E., Steinert P. M., Yuspa S., Goldman R. D. Dynamic aspects of the supramolecular organization of intermediate filament networks in cultured epidermal cells. Cell Motil. 1982;2(3):197–213. doi: 10.1002/cm.970020302. [DOI] [PubMed] [Google Scholar]
  10. Laemmli U. K. Cleavage of structural proteins during the assembly of the head of bacteriophage T4. Nature. 1970 Aug 15;227(5259):680–685. doi: 10.1038/227680a0. [DOI] [PubMed] [Google Scholar]
  11. Lazarides E. Intermediate filaments as mechanical integrators of cellular space. Nature. 1980 Jan 17;283(5744):249–256. doi: 10.1038/283249a0. [DOI] [PubMed] [Google Scholar]
  12. Olmsted J. B. Affinity purification of antibodies from diazotized paper blots of heterogeneous protein samples. J Biol Chem. 1981 Dec 10;256(23):11955–11957. [PubMed] [Google Scholar]
  13. Osborn M., Weber K. Intermediate filaments: cell-type-specific markers in differentiation and pathology. Cell. 1982 Dec;31(2 Pt 1):303–306. doi: 10.1016/0092-8674(82)90122-2. [DOI] [PubMed] [Google Scholar]
  14. Starger J. M., Brown W. E., Goldman A. E., Goldman R. D. Biochemical and immunological analysis of rapidly purified 10-nm filaments from baby hamster kidney (BHK-21) cells. J Cell Biol. 1978 Jul;78(1):93–109. doi: 10.1083/jcb.78.1.93. [DOI] [PMC free article] [PubMed] [Google Scholar]
  15. Steinert P. M., Idler W. W., Cabral F., Gottesman M. M., Goldman R. D. In vitro assembly of homopolymer and copolymer filaments from intermediate filament subunits of muscle and fibroblastic cells. Proc Natl Acad Sci U S A. 1981 Jun;78(6):3692–3696. doi: 10.1073/pnas.78.6.3692. [DOI] [PMC free article] [PubMed] [Google Scholar]
  16. Steinert P. M., Idler W. W., Poirier M. C., Katoh Y., Stoner G. D., Yuspa S. H. Subunit structure of the mouse epidermal keratin filament. Biochim Biophys Acta. 1979 Mar 27;577(1):11–21. doi: 10.1016/0005-2795(79)90003-5. [DOI] [PubMed] [Google Scholar]
  17. Steinert P. M., Idler W. W., Wantz M. L. Characterization of the keratin filament subunits unique to bovine snout epidermis. Biochem J. 1980 Jun 1;187(3):913–916. doi: 10.1042/bj1870913. [DOI] [PMC free article] [PubMed] [Google Scholar]
  18. Steinert P. M., Idler W. W., Zimmerman S. B. Self-assembly of bovine epidermal keratin filaments in vitro. J Mol Biol. 1976 Dec 15;108(3):547–567. doi: 10.1016/s0022-2836(76)80136-2. [DOI] [PubMed] [Google Scholar]
  19. Steinert P. M., Rice R. H., Roop D. R., Trus B. L., Steven A. C. Complete amino acid sequence of a mouse epidermal keratin subunit and implications for the structure of intermediate filaments. Nature. 1983 Apr 28;302(5911):794–800. doi: 10.1038/302794a0. [DOI] [PubMed] [Google Scholar]
  20. Steinert P. M. Structure of the three-chain unit of the bovine epidermal keratin filament. J Mol Biol. 1978 Jul 25;123(1):49–70. doi: 10.1016/0022-2836(78)90376-5. [DOI] [PubMed] [Google Scholar]
  21. Steinert P. M. The extraction and characterization of bovine epidermal alpha-keratin. Biochem J. 1975 Jul;149(1):39–48. doi: 10.1042/bj1490039. [DOI] [PMC free article] [PubMed] [Google Scholar]
  22. Steinert P. M., Zimmerman S. B., Starger J. M., Goldman R. D. Ten-nanometer filaments of hamster BHK-21 cells and epidermal keratin filaments have similar structures. Proc Natl Acad Sci U S A. 1978 Dec;75(12):6098–6101. doi: 10.1073/pnas.75.12.6098. [DOI] [PMC free article] [PubMed] [Google Scholar]
  23. Sun T. T., Green H. Immunofluorescent staining of keratin fibers in cultured cells. Cell. 1978 Jul;14(3):469–476. doi: 10.1016/0092-8674(78)90233-7. [DOI] [PubMed] [Google Scholar]
  24. Towbin H., Staehelin T., Gordon J. Electrophoretic transfer of proteins from polyacrylamide gels to nitrocellulose sheets: procedure and some applications. Proc Natl Acad Sci U S A. 1979 Sep;76(9):4350–4354. doi: 10.1073/pnas.76.9.4350. [DOI] [PMC free article] [PubMed] [Google Scholar]
  25. Tseng S. C., Jarvinen M. J., Nelson W. G., Huang J. W., Woodcock-Mitchell J., Sun T. T. Correlation of specific keratins with different types of epithelial differentiation: monoclonal antibody studies. Cell. 1982 Sep;30(2):361–372. doi: 10.1016/0092-8674(82)90234-3. [DOI] [PubMed] [Google Scholar]
  26. Tuszynski G. P., Frank E. D., Damsky C. H., Buck C. A., Warren L. The detection of smooth muscle desmin-like protein in BHK21/C13 fibroblasts. J Biol Chem. 1979 Jul 10;254(13):6138–6143. [PubMed] [Google Scholar]
  27. Weber K., Pringle J. R., Osborn M. Measurement of molecular weights by electrophoresis on SDS-acrylamide gel. Methods Enzymol. 1972;26:3–27. doi: 10.1016/s0076-6879(72)26003-7. [DOI] [PubMed] [Google Scholar]
  28. Zackroff R. V., Goldman R. D. In vitro assembly of intermediate filaments from baby hamster kidney (BHK-21) cells. Proc Natl Acad Sci U S A. 1979 Dec;76(12):6226–6230. doi: 10.1073/pnas.76.12.6226. [DOI] [PMC free article] [PubMed] [Google Scholar]

Articles from The Journal of Cell Biology are provided here courtesy of The Rockefeller University Press

RESOURCES