| Title: | Yeast endocytic adaptor AP-2 binds the stress sensor Mid2 and functions in polarized cell responses |
| Author(s): | Lazo B; Allwood EG; Smaczynska-de R; Snape ML; Ayscough KR; |
| Address: | "Department of Biomedical Science, University of Sheffield, Sheffield, S10 2TN, UK" |
| ISSN/ISBN: | 1600-0854 (Electronic) 1398-9219 (Print) 1398-9219 (Linking) |
| Abstract: | "The AP-2 complex is a heterotetrameric endocytic cargo-binding adaptor that facilitates uptake of membrane proteins during mammalian clathrin-mediated endocytosis. While budding yeast has clear homologues of all four AP-2 subunits which form a complex and localize to endocytic sites in vivo, the function of yeast AP-2 has remained enigmatic. Here, we demonstrate that AP-2 is required for hyphal growth in Candida albicans and polarized cell responses in Saccharomyces cerevisiae. Deletion of APM4, the cargo-binding mu subunit of AP-2, causes defects in pseudohyphal growth, generation of a mating projection and the cell wall damage response. In an apm4 null mutant, the cell wall stress sensor Mid2 is unable to relocalize to the tip of a mating projection following pheromone addition, or to the mother bud neck in response to cell wall damage. A direct binding interaction between Mid2 and the mu homology domain of Apm4 further supports a model in which AP-2 binds Mid2 to facilitate its internalization and relocalization in response to specific signals. Thus, Mid2 is the first cargo for AP-2 identified in yeast. We propose that endocytic recycling of Mid2 and other components is required for polarized cell responses ensuring cell wall deposition and is tightly monitored during cell growth" |
| Keywords: | Adaptor Protein Complex 2/*metabolism Candida albicans/metabolism/physiology Cell Polarity/*physiology Cell Wall/metabolism/physiology Clathrin/metabolism Endocytosis/*physiology Intracellular Signaling Peptides and Proteins/*metabolism Membrane Glycoprot; |
| Notes: | "MedlineChapa-y-Lazo, Bernardo Allwood, Ellen G Smaczynska-de Rooij, Iwona I Snape, Mary L Ayscough, Kathryn R eng BB/K002511/1/Biotechnology and Biological Sciences Research Council/United Kingdom G0601600/Medical Research Council/United Kingdom Research Support, Non-U.S. Gov't England 2014/01/28 Traffic. 2014 May; 15(5):546-57. doi: 10.1111/tra.12155. Epub 2014 Feb 25" |
