title: Microtubule minus end motors kinesin-14 and dynein drive nuclear congression in parallel pathways.
abstract: Microtubules (MTs) and associated motors play a central role in nuclear migration, which is crucial for diverse biological functions including cell division, polarity, and sexual reproduction. In this paper, we report a dual mechanism underlying nuclear congression during fission yeast karyogamy upon mating of haploid cells. Using microfluidic chambers for long-term imaging, we captured the precise timing of nuclear congression and identified two minus end-directed motors operating in parallel in this process. Kinesin-14 Klp2 associated with MTs may cross-link and slide antiparallel MTs emanating from the two nuclei, whereas dynein accumulating at spindle pole bodies (SPBs) may pull MTs nucleated from the opposite SPB. Klp2-dependent nuclear congression proceeds at constant speed, whereas dynein accumulation results in an increase of nuclear velocity over time. Surprisingly, the light intermediate chain Dli1, but not dynactin, is required for this previously unknown function of dynein. We conclude that efficient nuclear congression depends on the cooperation of two minus end-directed motors.
authors: Centre de Recherche and BioImaging Cell and Tissue Core Facility of the Institut Curie (PICT-IBiSA), Institut Curie, F-75248 Paris, France Centre National de la Recherche Scientifique, Unite Mixte de Recherche 144, F-75248 Paris, France.
authors: Kathleen
authors: K
authors: Scheffler
authors: Cell and Developmental Biology, University of Pennsylvania, Philadelphia, PA 19104.
authors: Refael
authors: R
authors: Minnes
authors: Centre de Recherche and BioImaging Cell and Tissue Core Facility of the Institut Curie (PICT-IBiSA), Institut Curie, F-75248 Paris, France Centre National de la Recherche Scientifique, Unite Mixte de Recherche 144, F-75248 Paris, France.
authors: Vincent
authors: V
authors: Fraisier
authors: Centre de Recherche and BioImaging Cell and Tissue Core Facility of the Institut Curie (PICT-IBiSA), Institut Curie, F-75248 Paris, France Centre National de la Recherche Scientifique, Unite Mixte de Recherche 144, F-75248 Paris, France.
authors: Anne
authors: A
authors: Paoletti
authors: Centre de Recherche and BioImaging Cell and Tissue Core Facility of the Institut Curie (PICT-IBiSA), Institut Curie, F-75248 Paris, France Centre National de la Recherche Scientifique, Unite Mixte de Recherche 144, F-75248 Paris, France Cell and Developmental Biology, University of Pennsylvania, Philadelphia, PA 19104 phong.tran@curie.fr.
authors: Phong T
authors: PT
authors: Tran
mesh_terms: D002467:Cell Nucleus / Q000378:metabolism*; D004398:Dyneins / Q000378:metabolism*; D008869:Microtubule-Associated Proteins / Q000378:metabolism*; D008870:Microtubules / Q000378:metabolism*; D021381:Protein Transport; D012568:Schizosaccharomyces / Q000378:metabolism* / Q000648:ultrastructure; D029702:Schizosaccharomyces pombe Proteins / Q000378:metabolism*
chemical_list: C502171:Klp2 protein, S pombe; D008869:Microtubule-Associated Proteins; D029702:Schizosaccharomyces pombe Proteins; C505433:Dhc1 protein, S pombe; D004398:Dyneins