Effects of the regulatory light chain phosphorylation of myosin II on mitosis and cytokinesis of mammalian cells
UMass Chan Affiliations
Department of PhysiologyDocument Type
Journal ArticlePublication Date
2000-08-17Keywords
Animals*Cell Cycle
Cell Division
Cell Line
Cells, Cultured
Green Fluorescent Proteins
Luminescent Proteins
Myosins
Phosphorylation
Recombinant Fusion Proteins
Biochemistry, Biophysics, and Structural Biology
Cellular and Molecular Physiology
Life Sciences
Medicine and Health Sciences
Metadata
Show full item recordAbstract
Myosin plays an important role in mitosis, especially during cytokinesis. Although it has been assumed that phosphorylation of regulatory light chain of myosin (RLC) controls motility of mammalian non-muscle cells, the functional significance of RLC phosphorylation remains uninvestigated. To address this problem, we have produced unphosphorylatable RLC (T18A/S19A RLC) and overexpressed it in COS-7 cells and normal rat kidney cells. Overexpression of T18A/S19A RLC but not wild type RLC almost completely abolished concanavalin A-induced receptor cap formation. The results indicate that myosin phosphorylation is critical for concanavalin A-induced gathering of surface receptors. T18A/S19A RLC overexpression resulted in the production of multinucleated cells, suggesting the failure of proper cell division in these cells. Video microscopic observation revealed that cells expressing T18A/S19A RLC showed abnormalities during mitosis in two respects. One is that the cells produced abnormal cleavage furrows, resulting in incomplete cytokinesis, which suggests that myosin phosphorylation is important for the normal recruitment of myosin molecules into the contractile ring structure. The other is that separation of chromosomes from the metaphase plate is disrupted in T18A/S19A RLC expressing cells, thus preventing proper transition from metaphase to anaphase. These results suggest that, in addition to cytokinesis, myosin and myosin phosphorylation play a role in the karyokinetic process.Source
J Biol Chem. 2000 Nov 3;275(44):34512-20. Link to article on publisher's siteDOI
10.1074/jbc.M003019200Permanent Link to this Item
http://hdl.handle.net/20.500.14038/42399PubMed ID
10944522Related Resources
Link to Article in PubMedae974a485f413a2113503eed53cd6c53
10.1074/jbc.M003019200