Molecular Biology of the Cell

Home Help [Feedback] [For Subscribers] [Archive] [Search] --
QUICK SEARCH:   [advanced]


     

MBC in Press, published online ahead of print January 30, 2008
Mol. Biol. Cell 10.1091/mbc.E07-05-0520

A more recent version of this article appeared on April 1, 2008
This Article
Right arrow Full Text (PDF)
Right arrow Supplemental Materials
Right arrow All Versions of this Article:
E07-05-0520v1
19/4/1474    most recent
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Gao, L.
Right arrow Articles by Bretscher, A.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Gao, L.
Right arrow Articles by Bretscher, A.

Submitted on June 1, 2007
Revised on January 14, 2008
Accepted on January 17, 2008

Analysis of Unregulated Formin Activity Reveals How Yeast Can Balance F-Actin Assembly between Different Microfilament-based Organizations

Lina Gao and Anthony Bretscher

Department of Molecular Biology and Genetics, Institute for Cell and Molecular Biology, Cornell University, Ithaca NY 14853

Monitoring Editor: Kerry Bloom

Formins are regulated actin nucleating proteins that are widespread among eukaryotes. Overexpression of unregulated formins in budding yeast is lethal and causes a massive accumulation of disorganized cable-like filaments. To explore the basis of this lethality, a cDNA library was screened to identify proteins whose overexpression could rescue the lethality conferred by unregulated Bnr1p expression. Three classes of suppressors encoding actin-binding proteins were isolated. One class encodes proteins that promote the assembly of actin cables (TPM1, TPM2 and ABP140), suggesting that the lethality was rescued by turning disorganized filaments into functional cables. The second class encodes proteins that bind G-actin (COF1, SRV2 and PFY1), indicating that reduction of the pool of actin available for cable formation may also rescue lethality. Consistent with this, pharmacological or genetic reduction of available actin also protected the cell from overproduction of unregulated Bnr1p. The third class consists of Las17p, an activator of the formin-independent Arp2/3p-dependent actin nucleation pathway. These results indicate that proper assembly of actin cables is sensitive to the appropriate balance of their constituents, and that input into one pathway for actin filament assembly can affect another. Thus, cells must have a way of ensuring a proper balance between actin assembly pathways.

Address correspondence to: Anthony Bretscher (apb5{at}cornell.edu)






Home Help [Feedback] [For Subscribers] [Archive] [Search] --
Copyright © 2008 by The American Society for Cell Biology. Terms of copyright protection, warranties, and disclaimers.