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The role of nucleoplasmin in chromatin assembly and disassembly

Chapter

Summary

Nucleoplasmin is the most abundant nuclear protein in Xenopus oocytes and eggs. The term ‘molecular chaperone’ was coined to describe its role in the assembly of the nucleosome subunits of chromatin. Although histones and DNA can self-assemble into nucleosomes, nucleoplasmin can facilitate this process in vitro by competing against non-specific charge interactions. In vivo nucleoplasmin binds histones H2A and H2B and transfers them to DNA. Another acidic nuclear protein, N1, binds and transfers histones H3 and H4. Nucleoplasmin has at least one other role in modulating chromatin structure in Xenopus eggs. It is required for the first stage of sperm chromatin decondensation. It binds and removes sperm basic proteins and replaces them by histones H2A and H2B, again forming nucleosomes, and resulting in decondensation of the compacted sperm chromatin. In addition we propose that the properties of the nuclear localization signal of nucleoplasmin can be explained by a model in which heat shock cognate protein hsc70 has a chaperone role in signal presentation during nuclear transport.

Keywords

Nuclear Localization Signal Xenopus Oocyte Sperm Nucleus Nucleolar Protein Xenopus Laevis Oocyte 
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References

  1. Almouzni, G. & Mechali, M. 1988 Assembly of spaced chromatin involvement of ATP and DNA topoisomerase activity. EMBO J. 7, 4355–4365.PubMedGoogle Scholar
  2. Burglin, T.R., Mattaj, I.W., Newmeyer, D.D., Zeller, R. & De Robertis, E.M. 1987 Cloning of nucleoplasmin from Xenopus laevis oocytes and analysis of its developmental expression. Genes Dev. 1, 97–107.PubMedCrossRefGoogle Scholar
  3. Cotten, M., Sealy, L. & Chalkley, R. 1986 Massive phosphorylation distinguishes Xenopus laevis nucleoplasmin isolated from oocytes or unfertilised eggs. Biochemistry 25, 5063–5069.PubMedCrossRefGoogle Scholar
  4. Dilworth, S.M., Black, S.J. & Laskey, R.A. 1987 Two complexes that contain histones are required for nucleo-some assembly in vitro: role of nucleoplasmin and N1 in Xenopus egg extracts. Cell 51, 1009–1018.PubMedCrossRefGoogle Scholar
  5. Dingwall, C. 1985 The accumulation of proteins in the nucleus. Trends biochem. Sci. 10(2), 64–66.CrossRefGoogle Scholar
  6. Dingwall, C. & Laskey, R.A. 1986 Protein import into the cell nucleus. A. Rev. Cell Biol. 2, 367–390.CrossRefGoogle Scholar
  7. Dingwall, C. & Laskey, R.A. 1991 Nuclear targeting sequences — a consensus? Trends biochem. Sci. 16, 478–481.PubMedCrossRefGoogle Scholar
  8. Dingwall, C., Sharnick, S.V. & Laskey, R.A. 1982 A polypeptide domain that specifies migration of nucleoplasmin into the nucleus. Cell 30, 449–458.PubMedCrossRefGoogle Scholar
  9. Dingwall, C., Dilworth, S.M., Black, S.J., Kearsey, S.E., Cox, L.S. & Laskey, R.A. 1987 Nucleoplasmin cDNA reveals polyglutamic acid tracts and a cluster of sequences homologous to putative nuclear localization signals. EMBO J. 6, 69–74.PubMedGoogle Scholar
  10. Earnshaw, W.C., Honda, B.M., Laskey, R.A. & Thomas, J.O. 1980 Assembly of nucleosomes: the reaction involving Xenopus laevis nucleoplasmin. Cell 21, 373–383.PubMedCrossRefGoogle Scholar
  11. Flynn, G.C., Chappell, T.G. & Rothman, J.E. 1989 Peptide binding and release by proteins implicated as catalysts of protein assembly. Science, Wash. 245, 385–390.CrossRefGoogle Scholar
  12. Kleinschmidt, J.A. & Franke, W.W. 1982 Soluble acidic complexes containing histones H3 and H4 in nuclei of Xenopus laevis oocytes. Cell 29, 799–809.PubMedCrossRefGoogle Scholar
  13. Kleinschmidt, J.A. & Seiter, A. 1988 Identification of domains involved in nuclear uptake and histone binding of protein N1 of Xenopus laevis. EMBO J. 7, 1605–1614.PubMedGoogle Scholar
  14. Kleinschmidt, J.A., Fortkamp, E., Krohne, G., Zentgraf, H. & Franke, W.W. 1985 Co-existence of two different types of soluble histone complexes in nuclei of Xenopus laevis oocytes. J. biol. Chem. 260, 1166–1176.PubMedGoogle Scholar
  15. Kleinschmidt, J.A., Dingwall, C., Maier, G. & Franke, W.W. 1986 Molecular characterisation of karyophilic, histone binding protein: cDNA cloning, amino acid sequence and expression of nuclear protein N1/N2 of Xenopus laevis. EMBO J. 5, 3547–3552.PubMedGoogle Scholar
  16. Kleinschmidt, J.A., Seiter, A. & Zentgraf, H. 1990 Nucleosome assembly in vitro: separate histone transfer and synergistic interaction of native histone complexes purified from nuclei of Xenopus laevis oocytes. EMBO J. 9, 1309–1318.PubMedGoogle Scholar
  17. Krohne, G. & Franke, W.W. 1980a Immunological identification and localization of the predominant nuclear protein of the amphibian oocyte nucleus. Proc. natn. Acad. Sci. U.S.A. 77, 1034–1038.CrossRefGoogle Scholar
  18. Krohne, G. & Franke, W.W. 1980b A major soluble acidic protein located in nuclei of diverse vertebrate species. Expl. Cell Res. 129, 167–189.CrossRefGoogle Scholar
  19. Laskey, R.A. 1983 Phosphorylation of nuclear proteins. Phil. Trans. R. Soc. Lond. B 302, 143–150.CrossRefGoogle Scholar
  20. Laskey, R.A. & Earnshaw, W.C. 1980 Nucleosome assembly. Nature, Lond. 286, 763–767.CrossRefGoogle Scholar
  21. Laskey, R.A., Honda, B.M., Mills, A.D. & Finch, J.T. 1978 Nucleosomes are assembled by an acidic protein which binds histones and transfers them to DNA. Nature, Lond. 275, 416–420.CrossRefGoogle Scholar
  22. Mills, A.D., Laskey, R.A., Black, P. & De Robertis, E.M. 1980 An acidic protein which assembles nucleosomes in vitro is the most abundant protein in Xenopus oocyte nuclei. J. molec. Biol. 139, 561–568.PubMedCrossRefGoogle Scholar
  23. Ohsumi, K. & Katagiri, C. 1991a Occurrence of H1 subtypes specific to pronuclei and cleavage-stage cell nuclei of anuran amphibians. Devi Biol. 147, 110–120.CrossRefGoogle Scholar
  24. Ohsumi, K. & Katagiri, C. 1991b Characterization of the ooplasmic factor inducing decondensation of and protamine removal from toad sperm nuclei: involvement of nucleoplasmin. Devl Biol. 148, 295–305.CrossRefGoogle Scholar
  25. Peculis, B. & Gall, J.G. 1992 Localization of the nucleolar protein NO 38 in amphibian oocytes. J. Cell Biol. 116, 1–14.PubMedCrossRefGoogle Scholar
  26. Philpott, A. & Leno, G.H. 1992 Nucleoplasmin remodels sperm chromatin in Xenopus egg extracts. Cell 69, 759–767.PubMedCrossRefGoogle Scholar
  27. Philpott, A., Leno, G.H. & Laskey, R.A. 1991 Sperm decondensation in Xenopus cytoplasm is mediated by nucleoplasmin. Cell 65, 569–578.PubMedCrossRefGoogle Scholar
  28. Robbins, J., Dilworth, S.M., Laskey, R.A. & Dingwall, C. 1991 Two interdependent basic domains in nucleoplasmin nuclear targeting sequence: identification of a class of bipartite nuclear targeting sequence. Cell 64, 615–623.PubMedCrossRefGoogle Scholar
  29. Sapp, M. & Worcell, A. 1990 Purification and mechanism of action of a nucleosome assembly factor from Xenopus oocytes. J. biol. Chem. 265, 9357–9365.PubMedGoogle Scholar
  30. Schmidt-Zachmann, M.S., Hugle-Dorr, B. & Frank, W.W. 1987 A constitutive nucleolar protein identified as a member of the nucleoplasmin family. EMBO J. 6, 1881–1890.PubMedGoogle Scholar
  31. Sealy, L., Cotten, M. & Chalkley, R. 1986 Xenopus nucleoplasmin: egg vs oocyte. Biochemistry 25, 3064–3072.PubMedCrossRefGoogle Scholar
  32. Shi, Y. & Thomas, J.O. 1992 The transport of proteins into the nucleus requires the 70-kilodalton heat shock protein or its cytosolic cognate. Molec. Cell Biol. 12, 2186–2192.PubMedGoogle Scholar
  33. Smith, S. & Stillman, B. 1989 Purification and characterization of CAF-1, a human cell factor required for chromain assembly during DNA replication in vitro. Cell 58, 15–25.PubMedCrossRefGoogle Scholar

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© Springer Science+Business Media Dordrecht 1993

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