Myosin V orientates the mitotic spindle in yeast.
Coordination of spindle orientation with the axis of cell division is an essential process in all eukaryotes. In addition to ensuring accurate chromosomal segregation, proper spindle orientation also establishes differential cell fates and proper morphogenesis. In both animal and yeast cells, this process is dependent on cytoplasmic microtubules interacting with the cortical actin-based cytoskeleton, although the motive force was unknown. Here we show that yeast Myo2, a myosin V that translocates along polarized actin cables into the bud, orientates the spindle early in the cell cycle by binding and polarizing the microtubule-associated protein Kar9 (refs 7-9). The tail domain of Myo2 that binds Kar9 also interacts with secretory vesicles and vacuolar elements, making it a pivotal component of yeast cell polarization.
Yin
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Department of Molecular Biology and Genetics, Cornell University, Ithaca, New York 14853, USA.
Pruyne
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Huffaker
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Bretscher
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D000199:Actins / Q000378:metabolism; D002352:Carrier Proteins / Q000378:metabolism / Q000502:physiology*; D002453:Cell Cycle; D008869:Microtubule-Associated Proteins / Q000378:metabolism; D008870:Microtubules / Q000378:metabolism; D018995:Myosin Heavy Chains; D024462:Myosin Type II; D024701:Myosin Type V; D009218:Myosins / Q000378:metabolism / Q000502:physiology*; D009687:Nuclear Proteins / Q000378:metabolism; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D029701:Saccharomyces cerevisiae Proteins; D004718:Saccharomycetales; D029702:Schizosaccharomyces pombe Proteins; D008941:Spindle Apparatus / Q000502:physiology*; D020798:Two-Hybrid System Techniques
D000199:Actins; D002352:Carrier Proteins; C110443:KAR9 protein, S cerevisiae; C077512:MYO2 protein, S cerevisiae; C434211:MYO2 protein, S pombe; D008869:Microtubule-Associated Proteins; D009687:Nuclear Proteins; D029701:Saccharomyces cerevisiae Proteins; D029702:Schizosaccharomyces pombe Proteins; C087665:kinesin-like protein 1; D024462:Myosin Type II; D024701:Myosin Type V; D018995:Myosin Heavy Chains; D009218:Myosins