Chromosome- and spindle-pole-derived signals generate an intrinsic code for spindle position and orientation.
Mitotic spindle positioning by cortical pulling forces defines the cell division axis and location, which is critical for proper cell division and development. Although recent work has identified developmental and extrinsic cues that regulate spindle orientation, the contribution of intrinsic signals to spindle positioning and orientation remains unclear. Here, we demonstrate that cortical force generation in human cells is controlled by distinct spindle-pole- and chromosome-derived signals that regulate cytoplasmic dynein localization. First, dynein exhibits a dynamic asymmetric cortical localization that is negatively regulated by spindle-pole proximity, resulting in spindle oscillations to centre the spindle within the cell. We find that this signal comprises the spindle-pole-localized polo-like kinase (Plk1), which regulates dynein localization by controlling the interaction between dynein-dynactin and its upstream cortical targeting factors NuMA and LGN. Second, a chromosome-derived RanGTP gradient restricts the localization of NuMA-LGN to the lateral cell cortex to define and maintain the spindle orientation axis. RanGTP acts in part through the nuclear localization sequence of NuMA to locally alter the ability of NuMA-LGN to associate with the cell cortex in the vicinity of chromosomes. We propose that these chromosome- and spindle-pole-derived gradients generate an intrinsic code to control spindle position and orientation.
Whitehead Institute, Nine Cambridge Center, Cambridge, Massachusetts 02142, USA.
Tomomi
T
Kiyomitsu
Iain M
IM
Cheeseman
D000595:Amino Acid Sequence; D000818:Animals; D034961:Antigens, Nuclear / Q000235:genetics / Q000378:metabolism; D015153:Blotting, Western; D018797:Cell Cycle Proteins / Q000235:genetics / Q000378:metabolism; D002502:Centrioles / Q000378:metabolism / Q000502:physiology; D020090:Chromosome Segregation / Q000502:physiology*; D056445:Cytoplasmic Dyneins / Q000235:genetics / Q000378:metabolism; D000072159:Dynactin Complex; D004398:Dyneins / Q000235:genetics / Q000378:metabolism; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism; D006367:HeLa Cells; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins / Q000235:genetics / Q000378:metabolism; D051379:Mice; D008856:Microscopy, Fluorescence; D008869:Microtubule-Associated Proteins / Q000235:genetics / Q000378:metabolism; D008938:Mitosis / Q000502:physiology*; D008954:Models, Biological; D008969:Molecular Sequence Data; D041681:NIH 3T3 Cells; D034521:Nuclear Matrix-Associated Proteins / Q000235:genetics / Q000378:metabolism; D011485:Protein Binding; D017346:Protein Serine-Threonine Kinases / Q000235:genetics / Q000378:metabolism; D011518:Proto-Oncogene Proteins / Q000235:genetics / Q000378:metabolism; D034622:RNA Interference; D015398:Signal Transduction / Q000502:physiology*; D008941:Spindle Apparatus / Q000378:metabolism / Q000502:physiology*; D020931:ran GTP-Binding Protein / Q000235:genetics / Q000378:metabolism; D000097869:Polo-Like Kinase 1
D034961:Antigens, Nuclear; D018797:Cell Cycle Proteins; D056445:Cytoplasmic Dyneins; D000072159:Dynactin Complex; D004398:Dyneins; D049452:Green Fluorescent Proteins; D047908:Intracellular Signaling Peptides and Proteins; D008869:Microtubule-Associated Proteins; D034521:Nuclear Matrix-Associated Proteins; D017346:Protein Serine-Threonine Kinases; D011518:Proto-Oncogene Proteins; D020931:ran GTP-Binding Protein; D000097869:Polo-Like Kinase 1; C102754:GPSM2 protein, human; C050045:NUMA1 protein, human