Journal of Cell Science, Vol 105, Issue 3 807-818, Copyright © 1993 by Company of Biologists

JOURNAL ARTICLES

ors12, a mammalian autonomously replicating DNA sequence, associates with the nuclear matrix in a cell cycle-dependent manner

DC Mah, PA Dijkwel, A Todd, V Klein, GB Price and M Zannis-Hadjopoulos
Department of Medicine, McGill University, Quebec, Canada.

Origin enriched sequence ors8 and ors12, have been isolated previously by extrusion of nascent CV-1 cell DNA from replication bubbles at the onset of S-phase. Both have been shown to direct autonomous DNA replication in vivo and in vitro. Here, we have examined the association of genomic ors8 and ors12 with the nuclear matrix in asynchronous and synchronized CV-1 cells. In asynchronously growing cells, ors8 was found to be randomly distributed, while ors12 was found to be enriched on the nuclear matrix. Using an in vitro binding assay, we determined that ors12 contains two attachment sites, each located in AT-rich domains. Surprisingly, in early and mid-S-phase cells, ors12 homologous sequences were recovered mainly from the DNA loops, while in late-S the majority had shifted to positions on the nuclear matrix. In contrast, the distribution of ors8 over the matrix and loop DNA fractions did not change during the cell cycle. By bromodeoxyuridine substitution of replicating DNA, followed by immunoprecipitation with anti-bromodeoxyuridine antibodies and PCR amplification, we demonstrated that ors12 replicates almost exclusively on the matrix in early and mid-S-phase; replicating ors8 was also found to be enriched on the matrix in early S-phase. Chase experiments showed that the ors12 sequences labelled with bromodeoxyuridine in the first 2 hours of S-phase remain attached to the nuclear matrix, resulting in an accumulation of ors12 on the nuclear matrix at the end of the S period.
CiteULike    Complore    Connotea    Del.icio.us    Digg    Reddit    Technorati    Twitter    What's this?

This article has been cited by other articles:

				L. Miccoli, I. Frouin, O. Novac, D. Di Paola, F. Harper, M. Zannis-Hadjopoulos, G. Maga, D. S. F. Biard, and J. F. Angulo The Human Stress-Activated Protein kin17 Belongs to the Multiprotein DNA Replication Complex and Associates In Vivo with Mammalian Replication Origins Mol. Cell. Biol., May 1, 2005; 25(9): 3814 - 3830. [Abstract] [Full Text] [PDF]

				O. Novac, D. Alvarez, C. E. Pearson, G. B. Price, and M. Zannis-Hadjopoulos The Human Cruciform-binding Protein, CBP, Is Involved in DNA Replication and Associates in Vivo with Mammalian Replication Origins J. Biol. Chem., March 22, 2002; 277(13): 11174 - 11183. [Abstract] [Full Text] [PDF]

				O. Novac, D. Matheos, F. D. Araujo, G. B. Price, and M. Zannis-Hadjopoulos In Vivo Association of Ku with Mammalian Origins of DNA Replication Mol. Biol. Cell, November 1, 2001; 12(11): 3386 - 3401. [Abstract] [Full Text] [PDF]