Lost your orientation? Find your way with PtdIns(3,4,5)P3!
Faithful chromosome segregation requires correct positioning of the spindle during mitosis. In this issue of Developmental Cell, Toyoshima et al. describe a new mechanism for spindle orientation involving phosphatidylinositol-3,4,5-triphosphate [PtdIns(3,4,5)P3]. They found that in metaphase cells, dynactin was associated with the cortex through the actin cytoskeleton, and accumulated in the midsections in a PtdIns(3,4,5)P3-dependent manner. Thus, PtdIns(3,4,5)P3 regulates spindle orientation through dynein-dynactin motor complexes.
Gachet
Yannick
Y
LBCMCP-CNRS UMR5088, Institut d'Exploration Fonctionelle des Génomes (IFR109), University of Toulouse, 118 route de Narbonne, 31062 Toulouse, France.
Tournier
Sylvie
S
D000199:Actins / Q000378:metabolism*; D016764:Cell Polarity; D003599:Cytoskeleton / Q000378:metabolism; D000072159:Dynactin Complex; D006367:HeLa Cells / Q000502:physiology; D006801:Humans; D008677:Metaphase / Q000502:physiology*; D008869:Microtubule-Associated Proteins / Q000378:metabolism*; D018129:Phosphatidylinositol Phosphates / Q000502:physiology*; D008941:Spindle Apparatus / Q000378:metabolism*
D000199:Actins; D000072159:Dynactin Complex; D008869:Microtubule-Associated Proteins; D018129:Phosphatidylinositol Phosphates; C060974:phosphatidylinositol 3,4,5-triphosphate