Format

Send to

Choose Destination
See comment in PubMed Commons below
Curr Biol. 2011 Feb 8;21(3):184-94. doi: 10.1016/j.cub.2011.01.012.

Modeling vesicle traffic reveals unexpected consequences for Cdc42p-mediated polarity establishment.

Author information

1
Department of Mathematics, Duke University, Durham, NC 27708, USA.

Abstract

BACKGROUND:

Polarization in yeast has been proposed to involve a positive feedback loop whereby the polarity regulator Cdc42p orients actin cables, which deliver vesicles carrying Cdc42p to the polarization site. Previous mathematical models treating Cdc42p traffic as a membrane-free flux suggested that directed traffic would polarize Cdc42p, but it remained unclear whether Cdc42p would become polarized without the membrane-free simplifying assumption.

RESULTS:

We present mathematical models that explicitly consider stochastic vesicle traffic via exocytosis and endocytosis, providing several new insights. Our findings suggest that endocytic cargo influences the timing of vesicle internalization in yeast. Moreover, our models provide quantitative support for the view that integral membrane cargo proteins would become polarized by directed vesicle traffic given the experimentally determined rates of vesicle traffic and diffusion. However, such traffic cannot effectively polarize the more rapidly diffusing Cdc42p in the model without making additional assumptions that seem implausible and lack experimental support.

CONCLUSIONS:

Our findings suggest that actin-directed vesicle traffic would perturb, rather than reinforce, polarization in yeast.

PMID:
21277209
PMCID:
PMC3052744
DOI:
10.1016/j.cub.2011.01.012
[Indexed for MEDLINE]
Free PMC Article
PubMed Commons home

PubMed Commons

0 comments
How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for Elsevier Science Icon for PubMed Central
    Loading ...
    Support Center