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. 1987 Jun 1;104(6):1553–1561. doi: 10.1083/jcb.104.6.1553

"Buttonin," a unique button-shaped microtubule-associated protein (75 kD) that decorates spindle microtubule surface hexagonally

PMCID: PMC2114500  PMID: 3584241

Abstract

A 75-kD protein was purified from sea urchin egg microtubule proteins through gel filtration. It enhanced the polymerization of porcine brain tubulin, but was not heat-stable and did not bind to calmodulin in the presence of calcium as demonstrated by calmodulin affinity column chromatography. Rotary shadowing of the freeze-etched 75-kD protein adsorbed on mica revealed the protein to be a spherical molecule (approximately 9 nm in diameter). Quick-freeze deep-etch electron microscopy revealed that the surface of microtubules polymerized with 75-kD protein was entirely covered with hexagonally packed, round, button-like structures that were quite uniform in shape and size (approximately 9 nm) and similar to the buttons observed on microtubules of mitotic spindles in vivo or microtubules isolated from mitotic spindles. Judging from calibration studies of molecular mass by gel filtration, the 75-kD protein probably exists in a dimeric form (approximately 150 kD) in its native condition. The stoichiometry of tubulin (dimer) versus 75-kD protein (dimer) in the polymerized pellet was 3-3.4:1. Hence, we concluded that the 75-kD protein was a unique microtubule-associated protein that formed the microtubule button in vivo and in vitro. We propose to name this protein "buttonin".

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Selected References

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  1. Amos L. A. Arrangement of high molecular weight associated proteins on purified mammalian brain microtubules. J Cell Biol. 1977 Mar;72(3):642–654. doi: 10.1083/jcb.72.3.642. [DOI] [PMC free article] [PubMed] [Google Scholar]
  2. Bloom G. S., Luca F. C., Collins C. A., Vallee R. B. Use of multiple monoclonal antibodies to characterize the major microtubule-associated protein in sea urchin eggs. Cell Motil. 1985;5(6):431–446. doi: 10.1002/cm.970050602. [DOI] [PubMed] [Google Scholar]
  3. Bloom G. S., Luca F. C., Vallee R. B. Microtubule-associated protein 1B: identification of a major component of the neuronal cytoskeleton. Proc Natl Acad Sci U S A. 1985 Aug;82(16):5404–5408. doi: 10.1073/pnas.82.16.5404. [DOI] [PMC free article] [PubMed] [Google Scholar]
  4. Bloom G. S., Schoenfeld T. A., Vallee R. B. Widespread distribution of the major polypeptide component of MAP 1 (microtubule-associated protein 1) in the nervous system. J Cell Biol. 1984 Jan;98(1):320–330. doi: 10.1083/jcb.98.1.320. [DOI] [PMC free article] [PubMed] [Google Scholar]
  5. Borisy G. G., Marcum J. M., Olmsted J. B., Murphy D. B., Johnson K. A. Purification of tubulin and associated high molecular weight proteins from porcine brain and characterization of microtubule assembly in vitro. Ann N Y Acad Sci. 1975 Jun 30;253:107–132. doi: 10.1111/j.1749-6632.1975.tb19196.x. [DOI] [PubMed] [Google Scholar]
  6. Bradford M. M. A rapid and sensitive method for the quantitation of microgram quantities of protein utilizing the principle of protein-dye binding. Anal Biochem. 1976 May 7;72:248–254. doi: 10.1006/abio.1976.9999. [DOI] [PubMed] [Google Scholar]
  7. Gottlieb R. A., Murphy D. B. Analysis of the microtubule-binding domain of MAP-2. J Cell Biol. 1985 Nov;101(5 Pt 1):1782–1789. doi: 10.1083/jcb.101.5.1782. [DOI] [PMC free article] [PubMed] [Google Scholar]
  8. Herzog W., Weber K. Fractionation of brain microtubule-associated proteins. Isolation of two different proteins which stimulate tubulin polymerization in vitro. Eur J Biochem. 1978 Dec 1;92(1):1–8. doi: 10.1111/j.1432-1033.1978.tb12716.x. [DOI] [PubMed] [Google Scholar]
  9. Heuser J. E., Salpeter S. R. Organization of acetylcholine receptors in quick-frozen, deep-etched, and rotary-replicated Torpedo postsynaptic membrane. J Cell Biol. 1979 Jul;82(1):150–173. doi: 10.1083/jcb.82.1.150. [DOI] [PMC free article] [PubMed] [Google Scholar]
  10. Hirokawa N., Bloom G. S., Vallee R. B. Cytoskeletal architecture and immunocytochemical localization of microtubule-associated proteins in regions of axons associated with rapid axonal transport: the beta,beta'-iminodipropionitrile-intoxicated axon as a model system. J Cell Biol. 1985 Jul;101(1):227–239. doi: 10.1083/jcb.101.1.227. [DOI] [PMC free article] [PubMed] [Google Scholar]
  11. Hirokawa N. Cross-linker system between neurofilaments, microtubules, and membranous organelles in frog axons revealed by the quick-freeze, deep-etching method. J Cell Biol. 1982 Jul;94(1):129–142. doi: 10.1083/jcb.94.1.129. [DOI] [PMC free article] [PubMed] [Google Scholar]
  12. Hirokawa N., Heuser J. E. Quick-freeze, deep-etch visualization of the cytoskeleton beneath surface differentiations of intestinal epithelial cells. J Cell Biol. 1981 Nov;91(2 Pt 1):399–409. doi: 10.1083/jcb.91.2.399. [DOI] [PMC free article] [PubMed] [Google Scholar]
  13. Hirokawa N., Takemura R., Hisanaga S. Cytoskeletal architecture of isolated mitotic spindle with special reference to microtubule-associated proteins and cytoplasmic dynein. J Cell Biol. 1985 Nov;101(5 Pt 1):1858–1870. doi: 10.1083/jcb.101.5.1858. [DOI] [PMC free article] [PubMed] [Google Scholar]
  14. Hisanaga S., Sakai H. Cytoplasmic dynein of the sea urchin egg. II. Purification, characterization and interactions with microtubules and Ca-calmodulin. J Biochem. 1983 Jan;93(1):87–98. doi: 10.1093/oxfordjournals.jbchem.a134182. [DOI] [PubMed] [Google Scholar]
  15. Huber G., Matus A. Immunocytochemical localization of microtubule-associated protein 1 in rat cerebellum using monoclonal antibodies. J Cell Biol. 1984 Feb;98(2):777–781. doi: 10.1083/jcb.98.2.777. [DOI] [PMC free article] [PubMed] [Google Scholar]
  16. Izant J. G., Weatherbee J. A., McIntosh J. R. A microtubule-associated protein antigen unique to mitotic spindle microtubules in PtK1 cells. J Cell Biol. 1983 Feb;96(2):424–434. doi: 10.1083/jcb.96.2.424. [DOI] [PMC free article] [PubMed] [Google Scholar]
  17. Keller T. C., 3rd, Rebhun L. I. Strongylocentrotus purpuratus spindle tubulin. I. Characteristics of its polymerization and depolymerization in vitro. J Cell Biol. 1982 Jun;93(3):788–796. doi: 10.1083/jcb.93.3.788. [DOI] [PMC free article] [PubMed] [Google Scholar]
  18. Kim H., Binder L. I., Rosenbaum J. L. The periodic association of MAP2 with brain microtubules in vitro. J Cell Biol. 1979 Feb;80(2):266–276. doi: 10.1083/jcb.80.2.266. [DOI] [PMC free article] [PubMed] [Google Scholar]
  19. 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]
  20. Lee Y. C., Wolff J. Calmodulin binds to both microtubule-associated protein 2 and tau proteins. J Biol Chem. 1984 Jan 25;259(2):1226–1230. [PubMed] [Google Scholar]
  21. Matus A., Bernhardt R., Hugh-Jones T. High molecular weight microtubule-associated proteins are preferentially associated with dendritic microtubules in brain. Proc Natl Acad Sci U S A. 1981 May;78(5):3010–3014. doi: 10.1073/pnas.78.5.3010. [DOI] [PMC free article] [PubMed] [Google Scholar]
  22. Murphy D. B., Borisy G. G. Association of high-molecular-weight proteins with microtubules and their role in microtubule assembly in vitro. Proc Natl Acad Sci U S A. 1975 Jul;72(7):2696–2700. doi: 10.1073/pnas.72.7.2696. [DOI] [PMC free article] [PubMed] [Google Scholar]
  23. Sakai H. The isolated mitotic apparatus and chromosome motion. Int Rev Cytol. 1978;55:22–48. [PubMed] [Google Scholar]
  24. Scholey J. M., Neighbors B., McIntosh J. R., Salmon E. D. Isolation of microtubules and a dynein-like MgATPase from unfertilized sea urchin eggs. J Biol Chem. 1984 May 25;259(10):6516–6525. [PubMed] [Google Scholar]
  25. Shelanski M. L., Gaskin F., Cantor C. R. Microtubule assembly in the absence of added nucleotides. Proc Natl Acad Sci U S A. 1973 Mar;70(3):765–768. doi: 10.1073/pnas.70.3.765. [DOI] [PMC free article] [PubMed] [Google Scholar]
  26. Shiomura Y., Hirokawa N. Colocalization of microtubule-associated protein 1A and microtubule-associated protein 2 on neuronal microtubules in situ revealed with double-label immunoelectron microscopy. J Cell Biol. 1987 Jun;104(6):1575–1578. doi: 10.1083/jcb.104.6.1575. [DOI] [PMC free article] [PubMed] [Google Scholar]
  27. Sobue K., Fujita M., Muramoto Y., Kakiuchi S. The calmodulin-binding protein in microtubules is tau factor. FEBS Lett. 1981 Sep 14;132(1):137–140. doi: 10.1016/0014-5793(81)80447-4. [DOI] [PubMed] [Google Scholar]
  28. Vallee R. B., Bloom G. S. Isolation of sea urchin egg microtubules with taxol and identification of mitotic spindle microtubule-associated proteins with monoclonal antibodies. Proc Natl Acad Sci U S A. 1983 Oct;80(20):6259–6263. doi: 10.1073/pnas.80.20.6259. [DOI] [PMC free article] [PubMed] [Google Scholar]
  29. Vallee R. B., Davis S. E. Low molecular weight microtubule-associated proteins are light chains of microtubule-associated protein 1 (MAP 1). Proc Natl Acad Sci U S A. 1983 Mar;80(5):1342–1346. doi: 10.1073/pnas.80.5.1342. [DOI] [PMC free article] [PubMed] [Google Scholar]
  30. Voter W. A., Erickson H. P. Electron microscopy of MAP 2 (microtubule-associated protein 2). J Ultrastruct Res. 1982 Sep;80(3):374–382. doi: 10.1016/s0022-5320(82)80051-8. [DOI] [PubMed] [Google Scholar]
  31. Weingarten M. D., Lockwood A. H., Hwo S. Y., Kirschner M. W. A protein factor essential for microtubule assembly. Proc Natl Acad Sci U S A. 1975 May;72(5):1858–1862. doi: 10.1073/pnas.72.5.1858. [DOI] [PMC free article] [PubMed] [Google Scholar]

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