title: Regulation of mitosis by the NIMA kinase involves TINA and its newly discovered partner, An-WDR8, at spindle pole bodies.
abstract: The NIMA kinase is required for mitotic nuclear pore complex disassembly and potentially controls other mitotic-specific events. To investigate this possibility, we imaged NIMA-green fluorescent protein (GFP) using four-dimensional spinning disk confocal microscopy. At mitosis NIMA-GFP locates to spindle pole bodies (SPBs), which contain Cdk1/cyclin B, followed by Aurora, TINA, and the BimC kinesin. NIMA promotes NPC disassembly in a spatially regulated manner starting near SPBs. NIMA is also required for TINA, a NIMA-interacting protein, to locate to SPBs during initiation of mitosis, and TINA is then necessary for locating NIMA back to SPBs during mitotic progression. To help expand the NIMA-TINA pathway, we affinity purified TINA and found it to uniquely copurify with An-WDR8, a WD40-domain protein conserved from humans to plants. Like TINA, An-WDR8 accumulates within nuclei during G2 but disperses from nuclei before locating to mitotic SPBs. Without An-WDR8, TINA levels are greatly reduced, whereas TINA is necessary for mitotic targeting of An-WDR8. Finally, we show that TINA is required to anchor mitotic microtubules to SPBs and, in combination with An-WDR8, for successful mitosis. The findings provide new insights into SPB targeting and indicate that the mitotic microtubule-anchoring system at SPBs involves WDR8 in complex with TINA.
authors.affiliation: Department of Molecular Genetics and Molecular, Cellular and Developmental Biology Program, Ohio State University, Columbus, OH 43210.
authors.forename: Kuo-Fang
authors.initials: KF
authors.lastname: Shen
authors.forename: Stephen A
authors.initials: SA
authors.lastname: Osmani
mesh_terms: D000595:Amino Acid Sequence; D001233:Aspergillus nidulans / Q000235:genetics*; D064096:Aurora Kinase A; D016203:CDC2 Protein Kinase / Q000235:genetics / Q000378:metabolism; D018797:Cell Cycle Proteins / Q000235:genetics*; D019926:Cyclin B / Q000235:genetics / Q000378:metabolism; D005656:Fungal Proteins / Q000235:genetics* / Q000378:metabolism; D016195:G2 Phase / Q000235:genetics; D049452:Green Fluorescent Proteins / Q000235:genetics; D016547:Kinesins; D018613:Microscopy, Confocal; D008938:Mitosis / Q000235:genetics*; D050258:Mitosis Modulators / Q000378:metabolism; D008969:Molecular Sequence Data; D000072380:NIMA-Related Kinase 1; D017346:Protein Serine-Threonine Kinases / Q000235:genetics*; D064048:Spindle Pole Bodies
chemical_list: C094560:BimC protein, Aspergillus nidulans; D018797:Cell Cycle Proteins; D019926:Cyclin B; D005656:Fungal Proteins; D050258:Mitosis Modulators; D049452:Green Fluorescent Proteins; D064096:Aurora Kinase A; C000606914:NEK1 protein, human; D000072380:NIMA-Related Kinase 1; D017346:Protein Serine-Threonine Kinases; D016203:CDC2 Protein Kinase; D016547:Kinesins