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. 1977 May 1;73(2):479–491. doi: 10.1083/jcb.73.2.479

Dynamic aspects of filopodial formation by reorganization of microfilaments

PMCID: PMC2109924  PMID: 558198

Abstract

The coelomocytes of the sea urchin, Strongylocentrotus droebachiensis, may be prevented from clotting with 50 mM ethylene glycol-bis(beta- aminoethyl)-N,N,N',N'-tetraacetate, 50 mM Tris-HCl, pH 7.8 and subsequently separated into various cell types on sucrose gradients. One cell type, the petaloid coelomocyte, spontaneously undergoes a striking morphological transformation to a form exhibiting numerous, t- in cytoplasmic projections (filopodia). Moreover, the transformation is reversible. Ultrastructurally, the formation of the filopodia results from a progressive reorganization of actin-containing filaments into bundles that are radially oriented. The formation of the filament bundles is initiated at the cell's periphery and proceeds inward. Simultaneously, the cytoplasm in between the bundles is withdrawn, exposing finger-like filopodia. Ultimately, the filopodia can be extended by up to four times their original length. Biochemically, actin is the most abundant protein in while cell homogenates and is extractable in milligram quantities via acetone powders. An actomyosin complex may also be isolated from these cells and is presumed to be active in producing the various forms of motility observed.

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Selected References

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  1. Abercrombie M., Heaysman J. E., Pegrum S. M. Locomotion of fibroblasts in culture. V. Surface marking with concanavalin A. Exp Cell Res. 1972 Aug;73(2):536–539. doi: 10.1016/0014-4827(72)90090-0. [DOI] [PubMed] [Google Scholar]
  2. BOOLOOTIAN R. A., GIESE A. C. Clotting of echinoderm coelomic fluid. J Exp Zool. 1959 Mar;140:207–229. doi: 10.1002/jez.1401400203. [DOI] [PubMed] [Google Scholar]
  3. Clarke M., Schatten G., Mazia D., Spudich J. A. Visualization of actin fibers associated with the cell membrane in amoebae of Dictyostelium discoideum. Proc Natl Acad Sci U S A. 1975 May;72(5):1758–1762. doi: 10.1073/pnas.72.5.1758. [DOI] [PMC free article] [PubMed] [Google Scholar]
  4. Hartwig J. H., Stossel T. P. Isolation and properties of actin, myosin, and a new actinbinding protein in rabbit alveolar macrophages. J Biol Chem. 1975 Jul 25;250(14):5696–5705. [PubMed] [Google Scholar]
  5. Ishikawa H., Bischoff R., Holtzer H. Formation of arrowhead complexes with heavy meromyosin in a variety of cell types. J Cell Biol. 1969 Nov;43(2):312–328. [PMC free article] [PubMed] [Google Scholar]
  6. Johnson P. T. The coelomic elements of sea urchins (Strongylocentrotus). 3. In vitro reaction to bacteria. J Invertebr Pathol. 1969 Jan;13(1):42–62. doi: 10.1016/0022-2011(69)90237-7. [DOI] [PubMed] [Google Scholar]
  7. Johnson P. T. The coelomic elements of sea urchins (Strongylocentrotus). I. The normal coelomocytes; their morphology and dynamics in hanging drops. J Invertebr Pathol. 1969 Jan;13(1):25–41. doi: 10.1016/0022-2011(69)90236-5. [DOI] [PubMed] [Google Scholar]
  8. Kirkpatrick F. Spectrin: current understanding of its physical, biochemical, and functional properties. Life Sci. 1976 Jul 1;19(1):1–17. doi: 10.1016/0024-3205(76)90368-4. [DOI] [PubMed] [Google Scholar]
  9. McNutt N. S., Culp L. A., Black P. H. Contact-inhibited revertant cell lines isolated from SV 40-transformed cells. IV. Microfilament distribution and cell shape in untransformed, transformed, and revertant Balb-c 3T3 cells. J Cell Biol. 1973 Feb;56(2):412–428. doi: 10.1083/jcb.56.2.412. [DOI] [PMC free article] [PubMed] [Google Scholar]
  10. Mooseker M. S., Tilney L. G. Organization of an actin filament-membrane complex. Filament polarity and membrane attachment in the microvilli of intestinal epithelial cells. J Cell Biol. 1975 Dec;67(3):725–743. doi: 10.1083/jcb.67.3.725. [DOI] [PMC free article] [PubMed] [Google Scholar]
  11. Perdue J. F. The distribution, ultrastructure, and chemistry of microfilaments in cultured chick embryo fibroblasts. J Cell Biol. 1973 Aug;58(2):265–283. doi: 10.1083/jcb.58.2.265. [DOI] [PMC free article] [PubMed] [Google Scholar]
  12. Pollack R., Osborn M., Weber K. Patterns of organization of actin and myosin in normal and transformed cultured cells. Proc Natl Acad Sci U S A. 1975 Mar;72(3):994–998. doi: 10.1073/pnas.72.3.994. [DOI] [PMC free article] [PubMed] [Google Scholar]
  13. Pollard T. D., Thomas S. M., Niederman R. Human platelet myosin. I. Purification by a rapid method applicable to other nonmuscle cells. Anal Biochem. 1974 Jul;60(1):258–266. doi: 10.1016/0003-2697(74)90152-3. [DOI] [PubMed] [Google Scholar]
  14. Schroeder T. E. Actin in dividing cells: contractile ring filaments bind heavy meromyosin. Proc Natl Acad Sci U S A. 1973 Jun;70(6):1688–1692. doi: 10.1073/pnas.70.6.1688. [DOI] [PMC free article] [PubMed] [Google Scholar]
  15. Spooner B. S., Yamada K. M., Wessells N. K. Microfilaments and cell locomotion. J Cell Biol. 1971 Jun;49(3):595–613. doi: 10.1083/jcb.49.3.595. [DOI] [PMC free article] [PubMed] [Google Scholar]
  16. Spudich J. A., Watt S. The regulation of rabbit skeletal muscle contraction. I. Biochemical studies of the interaction of the tropomyosin-troponin complex with actin and the proteolytic fragments of myosin. J Biol Chem. 1971 Aug 10;246(15):4866–4871. [PubMed] [Google Scholar]
  17. Taylor D. L., Condeelis J. S., Moore P. L., Allen R. D. The contractile basis of amoeboid movement. I. The chemical control of motility in isolated cytoplasm. J Cell Biol. 1973 Nov;59(2 Pt 1):378–394. doi: 10.1083/jcb.59.2.378. [DOI] [PMC free article] [PubMed] [Google Scholar]
  18. Tilney L. G. Actin filaments in the acrosomal reaction of Limulus sperm. Motion generated by alterations in the packing of the filaments. J Cell Biol. 1975 Feb;64(2):289–310. doi: 10.1083/jcb.64.2.289. [DOI] [PMC free article] [PubMed] [Google Scholar]
  19. Tilney L. G., Gibbins J. R. Microtubules in the formation and development of the primary mesenchyme in Arbacia punctulata. II. An experimental analysis of their role in development and maintenance of cell shape. J Cell Biol. 1969 Apr;41(1):227–250. doi: 10.1083/jcb.41.1.227. [DOI] [PMC free article] [PubMed] [Google Scholar]
  20. Tilney L. G., Hatano S., Ishikawa H., Mooseker M. S. The polymerization of actin: its role in the generation of the acrosomal process of certain echinoderm sperm. J Cell Biol. 1973 Oct;59(1):109–126. doi: 10.1083/jcb.59.1.109. [DOI] [PMC free article] [PubMed] [Google Scholar]
  21. 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]
  22. Wickus G., Gruenstein E., Robbins P. W., Rich A. Decrease in membrane-associated actin of fibroblasts after transformation by Rous sarcoma virus. Proc Natl Acad Sci U S A. 1975 Feb;72(2):746–749. doi: 10.1073/pnas.72.2.746. [DOI] [PMC free article] [PubMed] [Google Scholar]

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