Asymmetric recruitment of dynein to spindle poles and microtubules promotes proper spindle orientation in yeast.
The orientation of the mitotic spindle plays a key role in determining whether a polarized cell will divide symmetrically or asymmetrically. In most cell types, cytoplasmic dynein plays a critical role in spindle orientation. However, how dynein directs opposite spindle poles toward distinct and predetermined cell ends is poorly understood. Here, we show that dynein distributes preferentially to the spindle pole bodies (SPB) and astral microtubules (MTs) proximal to the bud in metaphase yeast cells. Dynein asymmetry depended on the bud neck kinases Elm1, Hsl1, and Gin4, on the spindle pole components Cnm67 and Cdk1, and on the B-type cyclins Clb1 and Clb2. Furthermore, phenotypic and genetic studies both indicated that dynein is unable to orient the spindle when it localizes to both poles and associated microtubules. Together, our data indicate that proper orientation of the spindle requires dynein to act on a single spindle pole.
Institute of Biochemistry, Biology Department, Swiss Federal Institute of Technology, ETH Zürich, 8093 Zürich, Switzerland.
Sandrine
S
Grava
Florian
F
Schaerer
Mahamadou
M
Faty
Peter
P
Philippsen
Yves
Y
Barral
D016203:CDC2 Protein Kinase / Q000502:physiology; D016764:Cell Polarity / Q000502:physiology*; D004398:Dyneins / Q000502:physiology*; D008870:Microtubules / Q000502:physiology* / Q000648:ultrastructure; D008938:Mitosis; D012441:Saccharomyces cerevisiae / Q000166:cytology / Q000502:physiology* / Q000648:ultrastructure; D029701:Saccharomyces cerevisiae Proteins / Q000502:physiology; D008941:Spindle Apparatus / Q000502:physiology* / Q000648:ultrastructure
D029701:Saccharomyces cerevisiae Proteins; D016203:CDC2 Protein Kinase; D004398:Dyneins