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Phospholipase C and myosin light chain kinase inhibition define a common step in actin regulation during cytokinesis

BACKGROUND: Phosphatidylinositol 4,5-bisphosphate (PIP(2)) is required for successful completion of cytokinesis. In addition, both PIP(2 )and phosphoinositide-specific phospholipase C (PLC) have been localized to the cleavage furrow of dividing mammalian cells. PLC hydrolyzes PIP(2 )to yield diacylg...

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Autores principales: Wong, Raymond, Fabian, Lacramioara, Forer, Arthur, Brill, Julie A
Formato: Texto
Lenguaje:English
Publicado: BioMed Central 2007
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1888687/
https://www.ncbi.nlm.nih.gov/pubmed/17509155
http://dx.doi.org/10.1186/1471-2121-8-15
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author Wong, Raymond
Fabian, Lacramioara
Forer, Arthur
Brill, Julie A
author_facet Wong, Raymond
Fabian, Lacramioara
Forer, Arthur
Brill, Julie A
author_sort Wong, Raymond
collection PubMed
description BACKGROUND: Phosphatidylinositol 4,5-bisphosphate (PIP(2)) is required for successful completion of cytokinesis. In addition, both PIP(2 )and phosphoinositide-specific phospholipase C (PLC) have been localized to the cleavage furrow of dividing mammalian cells. PLC hydrolyzes PIP(2 )to yield diacylglycerol (DAG) and inositol trisphosphate (IP(3)), which in turn induces calcium (Ca(2+) )release from the ER. Several studies suggest PIP(2 )must be hydrolyzed continuously for continued cleavage furrow ingression. The majority of these studies employ the N-substituted maleimide U73122 as an inhibitor of PLC. However, the specificity of U73122 is unclear, as its active group closely resembles the non-specific alkylating agent N-ethylmaleimide (NEM). In addition, the pathway by which PIP(2 )regulates cytokinesis remains to be elucidated. RESULTS: Here we compared the effects of U73122 and the structurally unrelated PLC inhibitor ET-18-OCH(3 )(edelfosine) on cytokinesis in crane-fly and Drosophila spermatocytes. Our data show that the effects of U73122 are indeed via PLC because U73122 and ET-18-OCH(3 )produced similar effects on cell morphology and actin cytoskeleton organization that were distinct from those caused by NEM. Furthermore, treatment with the myosin light chain kinase (MLCK) inhibitor ML-7 caused cleavage furrow regression and loss of both F-actin and phosphorylated myosin regulatory light chain from the contractile ring in a manner similar to treatment with U73122 and ET-18-OCH(3). CONCLUSION: We have used multiple inhibitors to examine the roles of PLC and MLCK, a predicted downstream target of PLC regulation, in cytokinesis. Our results are consistent with a model in which PIP(2 )hydrolysis acts via Ca(2+ )to activate myosin via MLCK and thereby control actin dynamics during constriction of the contractile ring.
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spelling pubmed-18886872007-06-06 Phospholipase C and myosin light chain kinase inhibition define a common step in actin regulation during cytokinesis Wong, Raymond Fabian, Lacramioara Forer, Arthur Brill, Julie A BMC Cell Biol Research Article BACKGROUND: Phosphatidylinositol 4,5-bisphosphate (PIP(2)) is required for successful completion of cytokinesis. In addition, both PIP(2 )and phosphoinositide-specific phospholipase C (PLC) have been localized to the cleavage furrow of dividing mammalian cells. PLC hydrolyzes PIP(2 )to yield diacylglycerol (DAG) and inositol trisphosphate (IP(3)), which in turn induces calcium (Ca(2+) )release from the ER. Several studies suggest PIP(2 )must be hydrolyzed continuously for continued cleavage furrow ingression. The majority of these studies employ the N-substituted maleimide U73122 as an inhibitor of PLC. However, the specificity of U73122 is unclear, as its active group closely resembles the non-specific alkylating agent N-ethylmaleimide (NEM). In addition, the pathway by which PIP(2 )regulates cytokinesis remains to be elucidated. RESULTS: Here we compared the effects of U73122 and the structurally unrelated PLC inhibitor ET-18-OCH(3 )(edelfosine) on cytokinesis in crane-fly and Drosophila spermatocytes. Our data show that the effects of U73122 are indeed via PLC because U73122 and ET-18-OCH(3 )produced similar effects on cell morphology and actin cytoskeleton organization that were distinct from those caused by NEM. Furthermore, treatment with the myosin light chain kinase (MLCK) inhibitor ML-7 caused cleavage furrow regression and loss of both F-actin and phosphorylated myosin regulatory light chain from the contractile ring in a manner similar to treatment with U73122 and ET-18-OCH(3). CONCLUSION: We have used multiple inhibitors to examine the roles of PLC and MLCK, a predicted downstream target of PLC regulation, in cytokinesis. Our results are consistent with a model in which PIP(2 )hydrolysis acts via Ca(2+ )to activate myosin via MLCK and thereby control actin dynamics during constriction of the contractile ring. BioMed Central 2007-05-17 /pmc/articles/PMC1888687/ /pubmed/17509155 http://dx.doi.org/10.1186/1471-2121-8-15 Text en Copyright © 2007 Wong et al; licensee BioMed Central Ltd. http://creativecommons.org/licenses/by/2.0 This is an Open Access article distributed under the terms of the Creative Commons Attribution License ( (http://creativecommons.org/licenses/by/2.0) ), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
spellingShingle Research Article
Wong, Raymond
Fabian, Lacramioara
Forer, Arthur
Brill, Julie A
Phospholipase C and myosin light chain kinase inhibition define a common step in actin regulation during cytokinesis
title Phospholipase C and myosin light chain kinase inhibition define a common step in actin regulation during cytokinesis
title_full Phospholipase C and myosin light chain kinase inhibition define a common step in actin regulation during cytokinesis
title_fullStr Phospholipase C and myosin light chain kinase inhibition define a common step in actin regulation during cytokinesis
title_full_unstemmed Phospholipase C and myosin light chain kinase inhibition define a common step in actin regulation during cytokinesis
title_short Phospholipase C and myosin light chain kinase inhibition define a common step in actin regulation during cytokinesis
title_sort phospholipase c and myosin light chain kinase inhibition define a common step in actin regulation during cytokinesis
topic Research Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1888687/
https://www.ncbi.nlm.nih.gov/pubmed/17509155
http://dx.doi.org/10.1186/1471-2121-8-15
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