QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

Vol. 16, Issue 3, 1296-1304, March 2005

This Article Full Text Full Text (PDF) Supplemental Material All Versions of this Article: E04-05-0430v1 16/3/1296    most recent Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Irazoqui, J. E. Articles by Lew, D. J. Search for Related Content PubMed PubMed Citation Articles by Irazoqui, J. E. Articles by Lew, D. J.

Opposing Roles for Actin in Cdc42p Polarization

Javier E. Irazoqui ^* , Audrey S. Howell ^*, Chandra L. Theesfeld, and Daniel J. Lew

Department of Pharmacology and Cancer Biology, Duke University Medical Center, Durham, NC 27710

Submitted May 24, 2004; Accepted December 15, 2004
Monitoring Editor: Anthony Bretscher

In animal and fungal cells, the monomeric GTPase Cdc42p is a key regulator of cell polarity that itself exhibits a polarized distribution in asymmetric cells. Previous work showed that in budding yeast, Cdc42p polarization is unaffected by depolymerization of the actin cytoskeleton (Ayscough et al., J. Cell Biol. 137, 399–416, 1997). Surprisingly, we now report that unlike complete actin depolymerization, partial actin depolymerization leads to the dispersal of Cdc42p from the polarization site in unbudded cells. We provide evidence that dispersal is due to endocytosis associated with cortical actin patches and that actin cables are required to counteract the dispersal and maintain Cdc42p polarity. Thus, although Cdc42p is initially polarized in an actin-independent manner, maintaining that polarity may involve a reinforcing feedback between Cdc42p and polarized actin cables to counteract the dispersing effects of actin-dependent endocytosis. In addition, we report that once a bud has formed, polarized Cdc42p becomes more resistant to dispersal, revealing an unexpected difference between unbudded and budded cells in the organization of the polarization site.

The online version of this article contains supplemental material at MBC Online (http://www.molbiolcell.org).

^* These authors contributed equally to this work.

Present address: Department of Molecular Biology, Massachusetts General Hospital, Harvard Medical Center, 50 Blossom St., 10 Wellman, Boston, MA 02114.

Address correspondence to: Daniel J. Lew (daniel.lew{at}duke.edu).

This article has been cited by other articles:

				P.-C. Tsai, S.-W. Lee, Y.-W. Liu, C.-W. Chu, K.-Y. Chen, J.-C. Ho, and F.-J. S. Lee Afi1p Functions as an Arf3p Polarization-specific Docking Factor for Development of Polarity J. Biol. Chem., June 13, 2008; 283(24): 16915 - 16927. [Abstract] [Full Text] [PDF]

				Y.-K. Kwon and K.-H. Cho Quantitative analysis of robustness and fragility in biological networks based on feedback dynamics Bioinformatics, April 1, 2008; 24(7): 987 - 994. [Abstract] [Full Text] [PDF]

				S. Aronov, R. Gelin-Licht, G. Zipor, L. Haim, E. Safran, and J. E. Gerst mRNAs Encoding Polarity and Exocytosis Factors Are Cotransported with the Cortical Endoplasmic Reticulum to the Incipient Bud in Saccharomyces cerevisiae Mol. Cell. Biol., May 1, 2007; 27(9): 3441 - 3455. [Abstract] [Full Text] [PDF]

				H.-O. Park and E. Bi Central Roles of Small GTPases in the Development of Cell Polarity in Yeast and Beyond Microbiol. Mol. Biol. Rev., March 1, 2007; 71(1): 48 - 96. [Abstract] [Full Text] [PDF]

				R. C. Aguilar, S. A. Longhi, J. D. Shaw, L.-Y. Yeh, S. Kim, A. Schon, E. Freire, A. Hsu, W. K. McCormick, H. A. Watson, et al. From the Cover: Epsin N-terminal homology domains perform an essential function regulating Cdc42 through binding Cdc42 GTPase-activating proteins. PNAS, March 14, 2006; 103(11): 4116 - 4121. [Abstract] [Full Text] [PDF]

				Y. E. France, C. Boyd, J. Coleman, and P. J. Novick The polarity-establishment component Bem1p interacts with the exocyst complex through the Sec15p subunit J. Cell Sci., March 1, 2006; 119(5): 876 - 888. [Abstract] [Full Text] [PDF]

				M. Iwase, J. Luo, S. Nagaraj, M. Longtine, H. B. Kim, B. K. Haarer, C. Caruso, Z. Tong, J. R. Pringle, and E. Bi Role of a Cdc42p Effector Pathway in Recruitment of the Yeast Septins to the Presumptive Bud Site Mol. Biol. Cell, March 1, 2006; 17(3): 1110 - 1125. [Abstract] [Full Text] [PDF]

				T. Kishimoto, T. Yamamoto, and K. Tanaka Defects in Structural Integrity of Ergosterol and the Cdc50p-Drs2p Putative Phospholipid Translocase Cause Accumulation of Endocytic Membranes, onto Which Actin Patches Are Assembled in Yeast Mol. Biol. Cell, December 1, 2005; 16(12): 5592 - 5609. [Abstract] [Full Text] [PDF]

				L. Kozubowski, J. R. Larson, and K. Tatchell Role of the Septin Ring in the Asymmetric Localization of Proteins at the Mother-Bud Neck in Saccharomyces cerevisiae Mol. Biol. Cell, August 1, 2005; 16(8): 3455 - 3466. [Abstract] [Full Text] [PDF]