Microtubules are dynamic cytoskeletal polymers that are required for mitosis, organelle motility and the establishment and maintenance of cell form. The microtubule cytoskeleton is dramatically reorganized each cell cycle: the extensive interphase microtubule array is replaced with a bipolar mitotic spindle, which is responsible for the accurate segregation of the duplicated chromosomes into two daughter cells during mitosis. The mitotic spindle is disassembled at the end of mitosis and the interphase microtubule array reformed. The long-term goal of our work is to understand how cells accomplish the remodeling of the microtubule array during each cell cycle. A key feature of our experimental approach is the analysis of microtubule behavior in living cells. In the proposed experiments, marks on the microtubule lattice will be created by local photoactivation of cells expressing tubulin tagged with a photoactivatible GFP variant. Chromosome motion will be monitored simultaneously using a GFPMicrotubules GFP-tagged kinetochore protein, CenpA. The movement of the photoactivated marks at prophase will be characterized and their role in nuclear envelope breakdown determined. The role of the centrosome in spindle microtubule movements will be examined by comparison of microtubule behavior in cells containing and lacking centrosomes. To determine the molecular motor proteins that are responsible for microtubule movements, individual mitotic motor proteins will be inactivated using post-transcriptional gene silencing, or RNAi. Cytoskeletal organization will be examined in fixed preparations using 3-D reconstructions of Z-series of images. The results will provide new information about the molecular basis for microtubule motions during spindle assembly and how these motions contribute to chromosome motion during mitosis. Learning how normal cells construct a mitotic spindle is an important first step towards understanding defective cell division in cancer.
| Balchand, Sai K; Mann, Barbara J; Wadsworth, Patricia (2016) Using Fluorescence Microscopy to Study Mitosis. Methods Mol Biol 1413:3-14 |
| Wadsworth, Pat (2015) TPX2. Curr Biol 25:R1156-8 |
| Collins, Elizabeth; Mann, Barbara J; Wadsworth, Patricia (2014) Eg5 restricts anaphase B spindle elongation in mammalian cells. Cytoskeleton (Hoboken) 71:136-44 |
| Wadsworth, Patricia; Lee, Wei-Lih; Murata, Takashi et al. (2011) Variations on theme: spindle assembly in diverse cells. Protoplasma 248:439-46 |
| Ma, Nan; Titus, Janel; Gable, Alyssa et al. (2011) TPX2 regulates the localization and activity of Eg5 in the mammalian mitotic spindle. J Cell Biol 195:87-98 |
| Ferenz, Nick P; Ma, Nan; Lee, Wei-Lih et al. (2010) Imaging protein dynamics in live mitotic cells. Methods 51:193-6 |
| Ma, Nan; Tulu, U S; Ferenz, Nick P et al. (2010) Poleward transport of TPX2 in the mammalian mitotic spindle requires dynein, Eg5, and microtubule flux. Mol Biol Cell 21:979-88 |
| Tulu, U Serdar; Ferenz, Nick P; Wadsworth, Patricia (2010) Photoactivatable green fluorescent protein-tubulin. Methods Cell Biol 97:81-90 |
| Miquelard-Garnier, Guillaume; Zimberlin, Jessica A; Sikora, Christian B et al. (2010) Polymer microlenses for quantifying cell sheet mechanics. Soft Matter 6:398-403 |
| Ferenz, Nick P; Gable, Alyssa; Wadsworth, Pat (2010) Mitotic functions of kinesin-5. Semin Cell Dev Biol 21:255-9 |
Showing the most recent 10 out of 22 publications
