The object of this proposal is to determine the relationship between nuclear structure and nuclear function. In order to begin approaching this large problem we will carry out a rigorous biochemical analysis of the protein components involved in nuclear structure. Such a study is now possible due to our recent discovery that nuclei reconstitute de novo around naked DNA added to an extract made from Xenopus eggs. We will use this nuclear reconstitution system to analyze: 1) The relation between DNA sequence and its effect on the assembly of nuclear structure. 2) In determining the size and arrangement of chromatin loops within the nucleus. 3) To identify important structural components involved in nuclear reconstitution, and ask in what sequence they are incorporated into a reforming nucleus; and 4) Using cell cycle regulators, determine the relationship between nuclear organization in interphase nuclei and mitotic chromosomes. This work should provide a solid foundation upon which to further study the role of nuclear structure in DNA replication, transcription, and recombination. It should also be useful in furthering our understanding of the molecular regulators controling the transition of G2 to M phase of the cell cycle. As such it should be of general interest to both cell and molecular biologists working on basic problems of eukaryotic cell organization.

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Project (R01)
Project #
5R01GM033523-03
Application #
3283355
Study Section
Molecular Cytology Study Section (CTY)
Project Start
1984-04-01
Project End
1987-03-31
Budget Start
1986-04-01
Budget End
1987-03-31
Support Year
3
Fiscal Year
1986
Total Cost
Indirect Cost
Name
University of California San Diego
Department
Type
Schools of Arts and Sciences
DUNS #
077758407
City
La Jolla
State
CA
Country
United States
Zip Code
92093
Zeitlin, Samantha G; Patel, Sheetal; Kavli, Bodil et al. (2005) Xenopus CENP-A assembly into chromatin requires base excision repair proteins. DNA Repair (Amst) 4:760-72
Yamaguchi, Ryuji; Newport, John (2003) A role for Ran-GTP and Crm1 in blocking re-replication. Cell 113:115-25
Harvey, Kevin J; Newport, John (2003) Metazoan origin selection: origin recognition complex chromatin binding is regulated by CDC6 recruitment and ATP hydrolysis. J Biol Chem 278:48524-8
Harvey, Kevin J; Newport, John (2003) CpG methylation of DNA restricts prereplication complex assembly in Xenopus egg extracts. Mol Cell Biol 23:6769-79
Hekmat-Nejad, M; You, Z; Yee, M C et al. (2000) Xenopus ATR is a replication-dependent chromatin-binding protein required for the DNA replication checkpoint. Curr Biol 10:1565-73
Michael, W M; Ott, R; Fanning, E et al. (2000) Activation of the DNA replication checkpoint through RNA synthesis by primase. Science 289:2133-7
Lin, X H; Walter, J; Scheidtmann, K et al. (1998) Protein phosphatase 2A is required for the initiation of chromosomal DNA replication. Proc Natl Acad Sci U S A 95:14693-8
Walter, J; Sun, L; Newport, J (1998) Regulated chromosomal DNA replication in the absence of a nucleus. Mol Cell 1:519-29
Guadagno, T M; Newport, J W (1996) Cdk2 kinase is required for entry into mitosis as a positive regulator of Cdc2-cyclin B kinase activity. Cell 84:73-82
Howe, J A; Newport, J W (1996) A developmental timer regulates degradation of cyclin E1 at the midblastula transition during Xenopus embryogenesis. Proc Natl Acad Sci U S A 93:2060-4

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