| Title: | Dynamic phosphoregulation of the cortical actin cytoskeleton and endocytic machinery revealed by real-time chemical genetic analysis |
| Author(s): | Sekiya-Kawasaki M; Groen AC; Cope MJ; Kaksonen M; Watson HA; Zhang C; Shokat KM; Wendland B; McDonald KL; McCaffery JM; Drubin DG; |
| Address: | "Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720-3202, USA" |
| ISSN/ISBN: | 0021-9525 (Print) 1540-8140 (Electronic) 0021-9525 (Linking) |
| Abstract: | "We used chemical genetics to control the activity of budding yeast Prk1p, which is a protein kinase that is related to mammalian GAK and AAK1, and which targets several actin regulatory proteins implicated in endocytosis. In vivo Prk1p inhibition blocked pheromone receptor endocytosis, and caused cortical actin patches to rapidly aggregate into large clumps that contained Abp1p, Sla2p, Pan1p, Sla1p, and Ent1p. Clump formation depended on Arp2p, suggesting that this phenotype might result from unregulated Arp2/3-stimulated actin assembly. Electron microscopy/immunoelectron microscopy analysis and tracking of the endocytic membrane marker FM4-64 revealed vesicles of likely endocytic origin within the actin clumps. Upon inhibitor washout, the actin clumps rapidly disassembled, and properly polarized actin patches reappeared. Our results suggest that actin clumps result from blockage at a normally transient step during which actin assembly is stimulated by endocytic proteins. Thus, we revealed tight phosphoregulation of an intrinsically dynamic, actin patch-related process, and propose that Prk1p negatively regulates the actin assembly-stimulating activity of endocytic proteins" |
| Keywords: | Actins/*metabolism Aurora Kinases Cytoskeleton/*metabolism Endocytosis/*physiology Fungal Proteins/genetics/*metabolism Protein Kinase C Protein Serine-Threonine Kinases/genetics/*metabolism Pyrazoles/chemistry Pyrimidines/chemistry Receptor Protein-Tyros; |
| Notes: | "MedlineSekiya-Kawasaki, Mariko Groen, Aaron Chris Cope, M Jamie T V Kaksonen, Marko Watson, Hadiya A Zhang, Chao Shokat, Kevan M Wendland, Beverly McDonald, Kent L McCaffery, J Michael Drubin, David G eng R01 GM042759/GM/NIGMS NIH HHS/ AI44009/AI/NIAID NIH HHS/ R37 GM042759/GM/NIGMS NIH HHS/ GM50399/GM/NIGMS NIH HHS/ GM42759/GM/NIGMS NIH HHS/ R01 AI044009/AI/NIAID NIH HHS/ GM60979/GM/NIGMS NIH HHS/ R01 GM060979/GM/NIGMS NIH HHS/ R01 GM050399/GM/NIGMS NIH HHS/ Research Support, Non-U.S. Gov't Research Support, U.S. Gov't, Non-P.H.S. Research Support, U.S. Gov't, P.H.S. 2003/09/04 J Cell Biol. 2003 Sep 1; 162(5):765-72. doi: 10.1083/jcb.200305077" |
