Evidence for a role of spindle matrix formation in cell cycle progression by antibody perturbation

• Published in: PloS one 2018-11, Vol.13 (11), p.e0208022-e0208022
• Main Authors: Yao, Changfu, Wang, Chao, Li, Yeran, Zavortink, Michael, Archambault, Vincent, Girton, Jack, Johansen, Kristen M, Johansen, Jørgen
• Format: Article
• Language: English
• Subjects: Animals; Animals, Genetically Modified; Antibodies; Antibodies - metabolism; Biochemistry; Biology and Life Sciences; Biophysics; Blocking antibodies; Cell cycle; Cell Cycle - drug effects; Cell Cycle - physiology; Cell Cycle Proteins - metabolism; Cell division; Cellular signal transduction; Chromosomes; Cloning; Colchicine; Colchicine - pharmacology; Cyclin B; Drosophila; Drosophila melanogaster; Drosophila Proteins - metabolism; Embryonic Development - drug effects; Embryonic Development - physiology; Embryos; Endoplasmic reticulum; Fruit flies; Gout suppressants; Insects; Kinases; Kinetochores; Localization; Macromolecules; Matrix protein; Mitosis; Molecular biology; Monoclonal antibodies; Perturbation; Phase transitions; Polo; Proteins; Regulators; Research and Analysis Methods; Spindle (Cytoplasm); Spindle Apparatus - metabolism; Tubulin Modulators - pharmacology
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0208022

In Drosophila it has recently been demonstrated that a spindle matrix in the form of a membrane-less macromolecular assembly embeds the microtubule-based spindle apparatus. In addition, two of its constituents, Megator and Chromator, were shown to function as spatial regulators of spindle checkpoint proteins. However, whether the spindle matrix plays a wider functional role in spatially regulating cell cycle progression factors was unknown. Here using a live imaging approach we provide evidence that a number of key cell cycle proteins such as Cyclin B, Polo, and Ran co-localize with the spindle matrix during mitosis. Furthermore, prevention of spindle matrix formation by injection of a function blocking antibody against the spindle matrix protein Chromator results in cell cycle arrest prior to nuclear envelope breakdown. In such embryos the spatial dynamics of Polo and Cyclin B enrichment at the nuclear rim and kinetochores is abrogated and Polo is not imported into the nucleus. This is in contrast to colchicine-arrested embryos where the wild-type dynamics of these proteins are maintained. Taken together these results suggest that spindle matrix formation may be a general requirement for the localization and proper dynamics of cell cycle factors promoting signaling events leading to cell cycle progression.