» Articles » PMID: 15353546

Robust Cell Polarity is a Dynamic State Established by Coupling Transport and GTPase Signaling

Overview
Journal J Cell Biol
Specialty Cell Biology
Date 2004 Sep 9
PMID 15353546
Citations 117
Authors
Affiliations
Soon will be listed here.
Abstract

Yeast cells can initiate bud formation at the G1/S transition in a cue-independent manner. Here, we investigate the dynamic nature of the polar cap and the regulation of the GTPase Cdc42 in the establishment of cell polarity. Using analysis of fluorescence recovery after photobleaching, we found that Cdc42 exchanged rapidly between the polar caps and cytosol and that this rapid exchange required its GTPase cycle. A previously proposed positive feedback loop involving actomyosin-based transport of the Cdc42 GTPase is required for the generation of robust cell polarity during bud formation in yeast. Inhibition of actin-based transport resulted in unstable Cdc42 polar caps. Unstable polarity was also observed in mutants lacking Bem1, a protein previously implicated in a feedback loop for Cdc42 activation through a signaling pathway. When Bem1 and actin were both inhibited, polarization completely failed. These results suggest that cell polarity is established through coupling of transport and signaling pathways and maintained actively by balance of flux.

Citing Articles

Regulation of yeast polarized exocytosis by phosphoinositide lipids.

Volpiana M, Nenadic A, Beh C Cell Mol Life Sci. 2024; 81(1):457.

PMID: 39560727 PMC: 11576722. DOI: 10.1007/s00018-024-05483-x.


Patterning of the cell cortex by Rho GTPases.

Bement W, Goryachev A, Miller A, von Dassow G Nat Rev Mol Cell Biol. 2024; 25(4):290-308.

PMID: 38172611 DOI: 10.1038/s41580-023-00682-z.


Redundancy and the role of protein copy numbers in the cell polarization machinery of budding yeast.

Brauns F, Inigo de la Cruz L, Daalman W, de Bruin I, Halatek J, Laan L Nat Commun. 2023; 14(1):6504.

PMID: 37845215 PMC: 10579396. DOI: 10.1038/s41467-023-42100-0.


Particle-based simulations reveal two positive feedback loops allow relocation and stabilization of the polarity site during yeast mating.

Guan K, Curtis E, Lew D, Elston T PLoS Comput Biol. 2023; 19(10):e1011523.

PMID: 37782676 PMC: 10569529. DOI: 10.1371/journal.pcbi.1011523.


A tractable physical model for the yeast polarity predicts epistasis and fitness.

Daalman W, Sweep E, Laan L Philos Trans R Soc Lond B Biol Sci. 2023; 378(1877):20220044.

PMID: 37004720 PMC: 10067261. DOI: 10.1098/rstb.2022.0044.


References
1.
Chant J, Herskowitz I . Genetic control of bud site selection in yeast by a set of gene products that constitute a morphogenetic pathway. Cell. 1991; 65(7):1203-12. DOI: 10.1016/0092-8674(91)90015-q. View

2.
Johnson D . Cdc42: An essential Rho-type GTPase controlling eukaryotic cell polarity. Microbiol Mol Biol Rev. 1999; 63(1):54-105. PMC: 98957. DOI: 10.1128/MMBR.63.1.54-105.1999. View

3.
Jaquenoud M, Peter M . Gic2p may link activated Cdc42p to components involved in actin polarization, including Bni1p and Bud6p (Aip3p). Mol Cell Biol. 2000; 20(17):6244-58. PMC: 86099. DOI: 10.1128/MCB.20.17.6244-6258.2000. View

4.
Becskei A, Seraphin B, Serrano L . Positive feedback in eukaryotic gene networks: cell differentiation by graded to binary response conversion. EMBO J. 2001; 20(10):2528-35. PMC: 125456. DOI: 10.1093/emboj/20.10.2528. View

5.
Bose I, Irazoqui J, Moskow J, Bardes E, Zyla T, Lew D . Assembly of scaffold-mediated complexes containing Cdc42p, the exchange factor Cdc24p, and the effector Cla4p required for cell cycle-regulated phosphorylation of Cdc24p. J Biol Chem. 2000; 276(10):7176-86. DOI: 10.1074/jbc.M010546200. View