Initial Polarized Bud Growth by Endocytic Recycling in the Absence of Actin Cable–dependent Vesicle Transport in Yeast
Open Access
- 1 April 2010
- journal article
- Published by American Society for Cell Biology (ASCB) in Molecular Biology of the Cell
- Vol. 21 (7), 1237-1252
- https://doi.org/10.1091/mbc.e09-05-0412
Abstract
The assembly of filamentous actin is essential for polarized bud growth in budding yeast. Actin cables, which are assembled by the formins Bni1p and Bnr1p, are thought to be the only actin structures that are essential for budding. However, we found that formin or tropomyosin mutants, which lack actin cables, are still able to form a small bud. Additional mutations in components for cortical actin patches, which are assembled by the Arp2/3 complex to play a pivotal role in endocytic vesicle formation, inhibited this budding. Genes involved in endocytic recycling were also required for small-bud formation in actin cable-less mutants. These results suggest that budding yeast possesses a mechanism that promotes polarized growth by local recycling of endocytic vesicles. Interestingly, the type V myosin Myo2p, which was thought to use only actin cables to track, also contributed to budding in the absence of actin cables. These results suggest that some actin network may serve as the track for Myo2p-driven vesicle transport in the absence of actin cables or that Myo2p can function independent of actin filaments. Our results also show that polarity regulators including Cdc42p were still polarized in mutants defective in both actin cables and cortical actin patches, suggesting that the actin cytoskeleton does not play a major role in cortical assembly of polarity regulators in budding yeast.Keywords
This publication has 93 references indexed in Scilit:
- Endocytosis Is Crucial for Cell Polarity and Apical Membrane Recycling in the Filamentous Fungus Aspergillus oryzaeEukaryotic Cell, 2009
- Aspergillus nidulans ArfB Plays a Role in Endocytosis and Polarized GrowthEukaryotic Cell, 2008
- The Tip Growth Apparatus ofAspergillus nidulansMolecular Biology of the Cell, 2008
- Endocytosis Optimizes the Dynamic Localization of Membrane Proteins that Regulate Cortical PolarityCell, 2007
- Spatial regulation of exocytosis and cell polarity: Yeast as a model for animal cellsFEBS Letters, 2007
- Central Roles of Small GTPases in the Development of Cell Polarity in Yeast and BeyondMicrobiology and Molecular Biology Reviews, 2007
- NPFXD-mediated Endocytosis Is Required for Polarity and Function of a Yeast Cell Wall Stress SensorMolecular Biology of the Cell, 2007
- Endocytic Recycling in Yeast Is Regulated by Putative Phospholipid Translocases and the Ypt31p/32p–Rcy1p PathwayMolecular Biology of the Cell, 2007
- The ARP2/3 complex: an actin nucleator comes of ageNature Reviews Molecular Cell Biology, 2006
- A Pathway for Association of Receptors, Adaptors, and Actin during Endocytic InternalizationCell, 2003