Home | Help | Feedback | Subscriptions | Archive | Search | Table of Contents

This Article PPT slides of all figures Alert me when this article is cited Services Email this article Similar articles in this journal Alert me to new content in the JCB Download to citation manager Citing Articles Citing Articles via CrossRef Citing Articles via Google Scholar Google Scholar Articles by LeBrasseur, N. Search for Related Content PubMed Articles by LeBrasseur, N. Social Bookmarking                            What's this?

© The Rockefeller University Press, 0021-9525/2003/9/751-a $5.00
The Journal of Cell Biology, Volume 162, Number 5, 751-a-751

Nucleotides choose origins

Nucleotide levels can alter replication initiation site selection. Debatisse/Elsevier

In vertebrate cells, not all potential DNA replication origins fire in each S phase, but it is unclear what parameters control that decision. Mauro Anglana, Michelle Debatisse (Institut Curie, Paris, France), and colleagues find that nucleotide availability can determine which origins are activated.

Under normal conditions (when nucleotides were readily available), initiation occurred predominantly at one site within the AMPD2 locus. Only in a few cases did minor sites fire instead. Firing of the dominant origin seems to prevent other nearby origins from initiating replication, as only an origin spaced far from the major origin was used simultaneously.

Cells with limited nucleotide availability, however, replicated from a wider variety of origins. Although the predominant origin was not used as often, simultaneous activation from multiple minor sites was more common. Firing efficiency of competent origins has been attributed mainly to epigenetic controls, including nuclear organization. But Debatisse says "things that are far simpler can also determine the choice of origin, including nucleotide pools. And it's completely reversible from one cell cycle to another."

A change in origin selection strategy probably equalizes genome replication times. Low nucleotide levels slowed replication fork progression, but the increased number of actively firing origins compensated for this difference, thus resulting in equally long S phases. Now, Debatisse hopes to identify proteins that localize to an origin in a nucleotide-dependent manner.

Reference:

Anglana, M., et al. 2003. Cell. 114:385–394.[CrossRef][Medline]

Nicole LeBrasseur

lebrasn{at}rockefeller.edu

CiteULike    Complore    Connotea    Del.icio.us    Digg    Facebook    Reddit    Technorati    Twitter    What's this?

This Article PPT slides of all figures Alert me when this article is cited Services Email this article Similar articles in this journal Alert me to new content in the JCB Download to citation manager Citing Articles Citing Articles via CrossRef Citing Articles via Google Scholar Google Scholar Articles by LeBrasseur, N. Search for Related Content PubMed Articles by LeBrasseur, N. Social Bookmarking                            What's this?