Dynamics of Cdc42 Network Embodies a Turing-type Mechanism of Yeast Cell Polarity

FEBS Lett. 2008 Apr 30;582(10):1437-43. doi: 10.1016/j.febslet.2008.03.029. Epub 2008 Mar 31.

Abstract

Complex biochemical networks can be understood by identifying their principal regulatory motifs and mode of action. We model the early phase of budding yeast cellular polarization and show that the biochemical processes in the presumptive bud site comprise a Turing-type mechanism. The roles of the prototypical activator and substrate are played by GTPase Cdc42 in its active and inactive states, respectively. We demonstrate that the nucleotide cycling of Cdc42 converts cellular energy into a stable cluster of activated Cdc42. This energy drives a continuous membrane-cytoplasmic exchange of the cluster components to counteract diffusive spread of the cluster. This exchange explains why only one bud forms per cell cycle, because the winner-takes-all competition of candidate sites inevitably selects a single site.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cell Polarity*
  • Fungal Proteins / metabolism*
  • Saccharomycetales / physiology*
  • cdc42 GTP-Binding Protein / metabolism*

Substances

  • Fungal Proteins
  • cdc42 GTP-Binding Protein