Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
Review
. 2004 Jul;5(7):686-91.
doi: 10.1038/sj.embor.7400185.

The replicon revisited: an old model learns new tricks in metazoan chromosomes

Mirit I Aladjem  1 , Ellen Fanning
Affiliations
Review

The replicon revisited: an old model learns new tricks in metazoan chromosomes

Mirit I Aladjem et al. EMBO Rep. 2004 Jul.

Abstract

The origins of DNA replication were proposed in the replicon model to be specified genetically by replicator elements that coordinate the initiation of DNA synthesis with gene expression and cell growth. Recent studies have identified DNA sequences in mammalian cells that fulfil the genetic criteria for replicators and are beginning to uncover the sequence requirements for the initiation of DNA replication. Mammalian replicators are com- posed of non-redundant modules that cooperate to direct initiation to specific chromosomal sites. Conversely, replicators do not show strong sequence similarity, and their ability to initiate replication depends on the chromosomal context and epigenetic factors, as well as their primary sequence. Here, we review the properties of metazoan replicators, and discuss the genetic and epigenetic factors that determine where and when DNA replication is initiated.

PubMed Disclaimer

Figures

Figure 1
Figure 1
The replicon model. A trans-acting protein encoded by the initiator gene was proposed to recognize a cis-acting sequence (the replicator) that controls the initiation of DNA replication in the replicon (Jacob et al, 1963).
Figure 2
Figure 2
Sequence features of metazoan replicators that are active at ectopic chromosomal sites. The genes surrounding the six replicators in five native loci are shown in blue (not to scale), and the elements required for initiation in the native locus are shown as hatched blue boxes. Mapped initiation regions in each replicator are indicated by purple triangles. In each ectopic replicator (yellow), the sequence elements in red have been shown to be required for full initiation activity. AG, asymmetric purine:pyrimidine regions; AT, AT-rich element; BEND, a sequence-directed bent DNA region; DHFR, dihydrofolate reductase; DNR, dinucleotide repeat; CpG, CpG island; LamB, lamin B; LCR, locus-control region; RIP60, replication-initiation region protein 60 kDa.
None
None
See this image and copyright information in PMC

Similar articles

See all similar articles

Cited by

See all "Cited by" articles

References

    1. Abdurashidova G, Danailov B, Ochem A, Triolo G, Djeliova V, Radulescu S, Vindigni A, Riva S, Falaschi A (2003) Localization of proteins bound to a replication origin of human DNA along the cell cycle. EMBO J 22: 4294–4303 - PMC - PubMed
    1. Aladjem MI, Groudine M, Brody LL, Dieken ES, Fournier RE, Wahl GM, Epner EM (1995) Participation of the human β-globin locus control region in initiation of DNA replication. Science 270: 815–819 - PubMed
    1. Aladjem MI, Rodewald LW, Kolman JL, Wahl GM (1998) Genetic dissection of a mammalian replicator in the human β-globin locus. Science 281: 1005–1009 - PubMed
    1. Aladjem MI, Rodewald LW, Lin CM, Bowman S, Cimbora DA, Brody LL, Epner EM, Groudine M, Wahl GM (2002) Replication initiation patterns in the β-globin loci of totipotent and differentiated murine cells: evidence for multiple initiation regions. Mol Cell Biol 22: 442–452 - PMC - PubMed
    1. Altman AL, Fanning E (2001) The Chinese hamster dihydrofolate reductase replication origin β is active at multiple ectopic chromosomal locations and requires specific DNA sequence elements for activity. Mol Cell Biol 21: 1098–1110 - PMC - PubMed

Publication types