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

This Article Full Text (PDF, 603K) 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 Wells, W. A. Search for Related Content PubMed Articles by Wells, W. A. Social Bookmarking                            What's this?

© The Rockefeller University Press, 0021-9525/2003/2/961-a $5.00
The Journal of Cell Biology, Volume 162, Number 6, 961-a-961

A daughter's size is not critical

Only cells with Ace2 (left) repress Cln3 expression in daughters. Heideman/NAS

The critical size model of cell division is so well established for budding yeast that, as Warren Heideman says, "it's on the wall of the Guinness Brewery." But now Tracy Laabs, Heideman (University of Wisconsin, Madison, WI), and colleagues have found that one of the pillars of the model has an alternative explanation.

The model states that cells only divide once they reach a critical size, which is why smaller daughters delay their division until they reach sizes comparable to those of their mothers. The Madison team found instead that daughters delay thanks to a daughter-localized G1 inhibitor called Ace2.After elimination of Ace2, mothers and daughters divided at the same time, so daughters divided at a smaller size than usual. An Ace2 mutant that was no longer localized to daughters also showed simultaneous division because both mothers and daughters were delayed.

Ace2 works at least in part by controlling levels of the G1 cyclin Cln3. In theory Ace2 could be resetting the critical size in daughters. But, says Heideman, "if you stick with critical size you have so many modifications that you are left with something very cumbersome."

He believes the cell couples growth rate and cell division rate without sensing size. "The critical size model was easily accepted by our minds because it was so elegant," he says, "but it may be hard [for the cell] to engineer."

Reference:

Laabs, T.L., et al. 2003. Proc. Natl. Acad. Sci. USA. 100:10275–10280.[Abstract/Free Full Text]

William A. Wells

wellsw{at}rockefeller.edu

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

This Article Full Text (PDF, 603K) 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 Wells, W. A. Search for Related Content PubMed Articles by Wells, W. A. Social Bookmarking                            What's this?