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Microinjection of the catalytic fragment of myosin light chain kinase into dividing cells: effects on mitosis and cytokinesis

Myosin light chain kinase (MLCK) is thought to regulate the contractile activity in smooth and non-muscle cells, and may play an important role in controlling the reorganization of the actin-myosin cytoskeleton during cell division. To test this hypothesis we have microinjected the 61-kD catalytic f...

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Detalles Bibliográficos
Formato: Texto
Lenguaje:English
Publicado: The Rockefeller University Press 1991
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2289109/
https://www.ncbi.nlm.nih.gov/pubmed/1874791
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description Myosin light chain kinase (MLCK) is thought to regulate the contractile activity in smooth and non-muscle cells, and may play an important role in controlling the reorganization of the actin-myosin cytoskeleton during cell division. To test this hypothesis we have microinjected the 61-kD catalytic fragment of MLCK into mitotic cells, and examined the effects of unregulated MLCK activity on cell division. The microinjection of active 61 kD causes both a significant delay in the transit time from nuclear envelope breakdown to anaphase onset, and an increase in motile surface activity during and after metaphase. Control experiments with intact MLCK or with inactive catalytic fragment suggest that these effects are specifically induced by the unregulated myosin light chain kinase activity. Immunofluorescence analysis suggests that delays in mitosis are coupled to disruptions of spindle structures, while increased surface motility may be related to changes in the organization of actin and myosin at the cell cortex. Most importantly, despite the expression of strong phenotypes, 61 kD- injected cells still form functional cleavage furrows that progress through cytokinesis at rates identical to those of control cells. Together, these results suggest that the activity of MLCK can affect mitosis and cortical activities, however additional control mechanisms are likely involved in the regulation of cytokinesis.
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spelling pubmed-22891092008-05-01 Microinjection of the catalytic fragment of myosin light chain kinase into dividing cells: effects on mitosis and cytokinesis J Cell Biol Articles Myosin light chain kinase (MLCK) is thought to regulate the contractile activity in smooth and non-muscle cells, and may play an important role in controlling the reorganization of the actin-myosin cytoskeleton during cell division. To test this hypothesis we have microinjected the 61-kD catalytic fragment of MLCK into mitotic cells, and examined the effects of unregulated MLCK activity on cell division. The microinjection of active 61 kD causes both a significant delay in the transit time from nuclear envelope breakdown to anaphase onset, and an increase in motile surface activity during and after metaphase. Control experiments with intact MLCK or with inactive catalytic fragment suggest that these effects are specifically induced by the unregulated myosin light chain kinase activity. Immunofluorescence analysis suggests that delays in mitosis are coupled to disruptions of spindle structures, while increased surface motility may be related to changes in the organization of actin and myosin at the cell cortex. Most importantly, despite the expression of strong phenotypes, 61 kD- injected cells still form functional cleavage furrows that progress through cytokinesis at rates identical to those of control cells. Together, these results suggest that the activity of MLCK can affect mitosis and cortical activities, however additional control mechanisms are likely involved in the regulation of cytokinesis. The Rockefeller University Press 1991-09-01 /pmc/articles/PMC2289109/ /pubmed/1874791 Text en This article is distributed under the terms of an Attribution–Noncommercial–Share Alike–No Mirror Sites license for the first six months after the publication date (see http://www.rupress.org/terms). After six months it is available under a Creative Commons License (Attribution–Noncommercial–Share Alike 4.0 Unported license, as described at http://creativecommons.org/licenses/by-nc-sa/4.0/).
spellingShingle Articles
Microinjection of the catalytic fragment of myosin light chain kinase into dividing cells: effects on mitosis and cytokinesis
title Microinjection of the catalytic fragment of myosin light chain kinase into dividing cells: effects on mitosis and cytokinesis
title_full Microinjection of the catalytic fragment of myosin light chain kinase into dividing cells: effects on mitosis and cytokinesis
title_fullStr Microinjection of the catalytic fragment of myosin light chain kinase into dividing cells: effects on mitosis and cytokinesis
title_full_unstemmed Microinjection of the catalytic fragment of myosin light chain kinase into dividing cells: effects on mitosis and cytokinesis
title_short Microinjection of the catalytic fragment of myosin light chain kinase into dividing cells: effects on mitosis and cytokinesis
title_sort microinjection of the catalytic fragment of myosin light chain kinase into dividing cells: effects on mitosis and cytokinesis
topic Articles
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2289109/
https://www.ncbi.nlm.nih.gov/pubmed/1874791