A Screen for Dynein Synthetic Lethals in Aspergillus nidulans Identifies Spindle Assembly Checkpoint Genes and Other Genes Involved in Mitosis

Corresponding author: N. Ronald Morris, Department of Pharmacology, UMDNJ-Robert Wood Johnson Medical School, 675 Hoes Lane, Piscataway, NJ 08854-5635, morrisnr{at}rwja.umdnj.edu (E-mail).

Communicating editor: R. H. DAVIS

Cytoplasmic dynein is a ubiquitously expressed microtubule motor involved in vesicle transport, mitosis, nuclear migration, and spindle orientation. In the filamentous fungus Aspergillus nidulans, inactivation of cytoplasmic dynein, although not lethal, severely impairs nuclear migration. The role of dynein in mitosis and vesicle transport in this organism is unclear. To investigate the complete range of dynein function in A. nidulans, we searched for synthetic lethal mutations that significantly reduced growth in the absence of dynein but had little effect on their own. We isolated 19 sld (synthetic lethality without dynein) mutations in nine different genes. Mutations in two genes exacerbate the nuclear migration defect seen in the absence of dynein. Mutations in six other genes, including sldA and sldB, show a strong synthetic lethal interaction with a mutation in the mitotic kinesin bimC and, thus, are likely to play a role in mitosis. Mutations in sldA and sldB also confer hypersensitivity to the microtubule-destabilizing drug benomyl. sldA and sldB were cloned by complementation of their mutant phenotypes using an A. nidulans autonomously replicating vector. Sequencing revealed homology to the spindle assembly checkpoint genes BUB1 and BUB3 from Saccharomyces cerevisiae. Genetic interaction between dynein and spindle assembly checkpoint genes, as well as other mitotic genes, indicates that A. nidulans dynein plays a role in mitosis. We suggest a model for dynein motor action in A. nidulans that can explain dynein involvement in both mitosis and nuclear distribution.

This article has been cited by other articles:

				S. Li, L. Du, G. Yuen, and S. D. Harris Distinct Ceramide Synthases Regulate Polarized Growth in the Filamentous Fungus Aspergillus nidulans Mol. Biol. Cell, March 1, 2006; 17(3): 1218 - 1227. [Abstract] [Full Text] [PDF]

				S. Li, C. E. Oakley, G. Chen, X. Han, B. R. Oakley, and X. Xiang Cytoplasmic Dynein's Mitotic Spindle Pole Localization Requires a Functional Anaphase-promoting Complex, {gamma}-Tubulin, and NUDF/LIS1 in Aspergillus nidulans Mol. Biol. Cell, August 1, 2005; 16(8): 3591 - 3605. [Abstract] [Full Text] [PDF]

				S. E. Gygax, C. P. Semighini, G. H. Goldman, and S. D. Harris SepBCTF4 Is Required for the Formation of DNA-Damage-Induced UvsCRAD51 Foci in Aspergillus nidulans Genetics, March 1, 2005; 169(3): 1391 - 1402. [Abstract] [Full Text] [PDF]

				C. L. Pearson, K. Xu, K. E. Sharpless, and S. D. Harris MesA, a Novel Fungal Protein Required for the Stabilization of Polarity Axes in Aspergillus nidulans Mol. Biol. Cell, August 1, 2004; 15(8): 3658 - 3672. [Abstract] [Full Text] [PDF]

				W. Su, S. Li, B. R. Oakley, and X. Xiang Dual-Color Imaging of Nuclear Division and Mitotic Spindle Elongation in Live Cells of Aspergillus nidulans Eukaryot. Cell, April 1, 2004; 3(2): 553 - 556. [Abstract] [Full Text] [PDF]

				N. L. Prigozhina, C. E. Oakley, A. M. Lewis, T. Nayak, S. A. Osmani, and B. R. Oakley {gamma}-Tubulin Plays an Essential Role in the Coordination of Mitotic Events Mol. Biol. Cell, March 1, 2004; 15(3): 1374 - 1386. [Abstract] [Full Text] [PDF]

				C. W. Pitt, E. Moreau, P. A. Lunness, and J. H. Doonan The pot1+ homologue in Aspergillus nidulans is required for ordering mitotic events J. Cell Sci., January 15, 2004; 117(2): 199 - 209. [Abstract] [Full Text] [PDF]

				A. Yamamoto and Y. Hiraoka Cytoplasmic dynein in fungi: insights from nuclear migration J. Cell Sci., November 15, 2003; 116(22): 4501 - 4512. [Abstract] [Full Text] [PDF]

				V. P. Efimov Roles of NUDE and NUDF Proteins of Aspergillus nidulans: Insights from Intracellular Localization and Overexpression Effects Mol. Biol. Cell, March 1, 2003; 14(3): 871 - 888. [Abstract] [Full Text] [PDF]

				K. Miura, E. D. Bowman, R. Simon, A. C. Peng, A. I. Robles, R. T. Jones, T. Katagiri, P. He, H. Mizukami, L. Charboneau, et al. Laser Capture Microdissection and Microarray Expression Analysis of Lung Adenocarcinoma Reveals Tobacco Smoking- and Prognosis-related Molecular Profiles Cancer Res., June 1, 2002; 62(11): 3244 - 3250. [Abstract] [Full Text] [PDF]

				E. Fuchs and I. Karakesisoglou Bridging cytoskeletal intersections Genes & Dev., January 1, 2001; 15(1): 1 - 14. [Full Text]

				P. Kalitsis, E. Earle, K. J. Fowler, and K.H. A. Choo Bub3 gene disruption in mice reveals essential mitotic spindle checkpoint function during early embryogenesis Genes & Dev., September 15, 2000; 14(18): 2277 - 2282. [Abstract] [Full Text]

				V. P. Efimov and N. R. Morris The LIS1-related NUDF Protein of Aspergillus nidulans Interacts with the Coiled-Coil Domain of the NUDE/RO11 Protein J. Cell Biol., August 7, 2000; 150(3): 681 - 688. [Abstract] [Full Text] [PDF]

				N. Osherov and G. May Conidial Germination in Aspergillus nidulans Requires RAS Signaling and Protein Synthesis Genetics, June 1, 2000; 155(2): 647 - 656. [Abstract] [Full Text]

				J. L. Paluh, E. Nogales, B. R. Oakley, K. McDonald, A. L. Pidoux, and W. Z. Cande A Mutation in gamma -Tubulin Alters Microtubule Dynamics and Organization and Is Synthetically Lethal with the Kinesin-like Protein Pkl1p Mol. Biol. Cell, April 1, 2000; 11(4): 1225 - 1239. [Abstract] [Full Text]

				N. R. Morris , M.D. Nuclear Migration: From Fungi to the Mammalian Brain J. Cell Biol., March 20, 2000; 148(6): 1097 - 1102. [Abstract] [Full Text] [PDF]

				A. G. Davies, C. A. Spike, J. E. Shaw, and R. K. Herman Functional Overlap Between the mec-8 Gene and Five sym Genes in Caenorhabditis elegans Genetics, September 1, 1999; 153(1): 117 - 134. [Abstract] [Full Text]

				M. J. Martinez-Exposito, K. B. Kaplan, J. Copeland, and P. K. Sorger Retention of the Bub3 checkpoint protein on lagging chromosomes PNAS, July 20, 1999; 96(15): 8493 - 8498. [Abstract] [Full Text] [PDF]

				A. Habura, I. Tikhonenko, R. L. Chisholm, and M. P. Koonce Interaction Mapping of a Dynein Heavy Chain. IDENTIFICATION OF DIMERIZATION AND INTERMEDIATE-CHAIN BINDING DOMAINS J. Biol. Chem., May 28, 1999; 274(22): 15447 - 15453. [Abstract] [Full Text] [PDF]

				S. M. Beckwith, C. H. Roghi, B. Liu, and N. Ronald Morris The "8-kD" Cytoplasmic Dynein Light Chain Is Required for Nuclear Migration and for Dynein Heavy Chain Localization in Aspergillus nidulans J. Cell Biol., November 30, 1998; 143(5): 1239 - 1247. [Abstract] [Full Text] [PDF]

				G.K.T. Chan, B.T. Schaar, and T.J. Yen Characterization of the Kinetochore Binding Domain of CENP-E Reveals Interactions with the Kinetochore Proteins CENP-F and hBUBR1 J. Cell Biol., October 5, 1998; 143(1): 49 - 63. [Abstract] [Full Text] [PDF]