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Regulation of Macropinocytosis by Diacylglycerol Kinase ζ

Macropinosomes arise from the closure of plasma membrane ruffles to bring about the non-selective uptake of nutrients and solutes into cells. The morphological changes underlying ruffle formation and macropinosome biogenesis are driven by actin cytoskeleton rearrangements under the control of the Rh...

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Autores principales: Ard, Ryan, Mulatz, Kirk, Pomoransky, Julia L., Parks, Robin J., Trinkle-Mulcahy, Laura, Bell, John C., Gee, Stephen H.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Public Library of Science 2015
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4689489/
https://www.ncbi.nlm.nih.gov/pubmed/26701304
http://dx.doi.org/10.1371/journal.pone.0144942
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author Ard, Ryan
Mulatz, Kirk
Pomoransky, Julia L.
Parks, Robin J.
Trinkle-Mulcahy, Laura
Bell, John C.
Gee, Stephen H.
author_facet Ard, Ryan
Mulatz, Kirk
Pomoransky, Julia L.
Parks, Robin J.
Trinkle-Mulcahy, Laura
Bell, John C.
Gee, Stephen H.
author_sort Ard, Ryan
collection PubMed
description Macropinosomes arise from the closure of plasma membrane ruffles to bring about the non-selective uptake of nutrients and solutes into cells. The morphological changes underlying ruffle formation and macropinosome biogenesis are driven by actin cytoskeleton rearrangements under the control of the Rho GTPase Rac1. We showed previously that Rac1 is activated by diacylglycerol kinase ζ (DGKζ), which phosphorylates diacylglycerol to yield phosphatidic acid. Here, we show DGKζ is required for optimal macropinocytosis induced by growth factor stimulation of mouse embryonic fibroblasts. Time-lapse imaging of live cells and quantitative analysis revealed DGKζ was associated with membrane ruffles and nascent macropinosomes. Macropinocytosis was attenuated in DGKζ-null cells, as determined by live imaging and vaccinia virus uptake experiments. Moreover, macropinosomes that did form in DGKζ-null cells were smaller than those found in wild type cells. Rescue of this defect required DGKζ catalytic activity, consistent with it also being required for Rac1 activation. A constitutively membrane bound DGKζ mutant substantially increased the size of macropinosomes and potentiated the effect of a constitutively active Rac1 mutant on macropinocytosis. Collectively, our results suggest DGKζ functions in concert with Rac1 to regulate macropinocytosis.
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spelling pubmed-46894892015-12-31 Regulation of Macropinocytosis by Diacylglycerol Kinase ζ Ard, Ryan Mulatz, Kirk Pomoransky, Julia L. Parks, Robin J. Trinkle-Mulcahy, Laura Bell, John C. Gee, Stephen H. PLoS One Research Article Macropinosomes arise from the closure of plasma membrane ruffles to bring about the non-selective uptake of nutrients and solutes into cells. The morphological changes underlying ruffle formation and macropinosome biogenesis are driven by actin cytoskeleton rearrangements under the control of the Rho GTPase Rac1. We showed previously that Rac1 is activated by diacylglycerol kinase ζ (DGKζ), which phosphorylates diacylglycerol to yield phosphatidic acid. Here, we show DGKζ is required for optimal macropinocytosis induced by growth factor stimulation of mouse embryonic fibroblasts. Time-lapse imaging of live cells and quantitative analysis revealed DGKζ was associated with membrane ruffles and nascent macropinosomes. Macropinocytosis was attenuated in DGKζ-null cells, as determined by live imaging and vaccinia virus uptake experiments. Moreover, macropinosomes that did form in DGKζ-null cells were smaller than those found in wild type cells. Rescue of this defect required DGKζ catalytic activity, consistent with it also being required for Rac1 activation. A constitutively membrane bound DGKζ mutant substantially increased the size of macropinosomes and potentiated the effect of a constitutively active Rac1 mutant on macropinocytosis. Collectively, our results suggest DGKζ functions in concert with Rac1 to regulate macropinocytosis. Public Library of Science 2015-12-23 /pmc/articles/PMC4689489/ /pubmed/26701304 http://dx.doi.org/10.1371/journal.pone.0144942 Text en © 2015 Ard et al http://creativecommons.org/licenses/by/4.0/ This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are properly credited.
spellingShingle Research Article
Ard, Ryan
Mulatz, Kirk
Pomoransky, Julia L.
Parks, Robin J.
Trinkle-Mulcahy, Laura
Bell, John C.
Gee, Stephen H.
Regulation of Macropinocytosis by Diacylglycerol Kinase ζ
title Regulation of Macropinocytosis by Diacylglycerol Kinase ζ
title_full Regulation of Macropinocytosis by Diacylglycerol Kinase ζ
title_fullStr Regulation of Macropinocytosis by Diacylglycerol Kinase ζ
title_full_unstemmed Regulation of Macropinocytosis by Diacylglycerol Kinase ζ
title_short Regulation of Macropinocytosis by Diacylglycerol Kinase ζ
title_sort regulation of macropinocytosis by diacylglycerol kinase ζ
topic Research Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4689489/
https://www.ncbi.nlm.nih.gov/pubmed/26701304
http://dx.doi.org/10.1371/journal.pone.0144942
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