Activation of Cdc42 is necessary for sustained oscillations of Ca2+ and PIP2 stimulated by antigen in RBL mast cells
Antigen stimulation of mast cells via FcεRI, the high-affinity receptor for IgE, triggers a signaling cascade that requires Ca2+ mobilization for exocytosis of secretory granules during the allergic response. To characterize the role of Rho GTPases in FcεRI signaling, we utilized a mutant RBL cell l...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
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The Company of Biologists
2014-07-01
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| Series: | Biology Open |
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| Online Access: | http://bio.biologists.org/content/3/8/700 |
| _version_ | 1818673230030831616 |
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| author | Marcus M. Wilkes Joshua D. Wilson Barbara Baird David Holowka |
| author_facet | Marcus M. Wilkes Joshua D. Wilson Barbara Baird David Holowka |
| author_sort | Marcus M. Wilkes |
| collection | DOAJ |
| description | Antigen stimulation of mast cells via FcεRI, the high-affinity receptor for IgE, triggers a signaling cascade that requires Ca2+ mobilization for exocytosis of secretory granules during the allergic response. To characterize the role of Rho GTPases in FcεRI signaling, we utilized a mutant RBL cell line, B6A4C1, that is deficient in antigen-stimulated Cdc42 activation important for these processes. Recently the importance of stimulated intracellular oscillations has emerged, and we find that B6A4C1 cells exhibit severely attenuated Ca2+ oscillations in response to antigen, which are restored to wild-type RBL-2H3 levels by expression of constitutively active Cdc42 G12V or by a GEF for Cdc42, DOCK7, but not when the C-terminal di-arginine motif of active Cdc42 is mutated to di-glutamine. We found that antigen-stimulated FcεRI endocytosis, which occurs independently of Ca2+ mobilization, is also defective in B6A4C1 cells, and Cdc42 G12V reconstitutes this response as well. Thus, activation of Cdc42 occurs prior to and is critical for antigen-stimulated pathways leading separately to both Ca2+ mobilization and receptor endocytosis. Accounting for these downstream functional consequences, we show that Cdc42 G12V reconstitutes antigen-stimulated oscillations of phosphatidylinositol 4,5-bisphosphate (PIP2) at the plasma membrane in mutant B6A4C1 cells, pointing to Cdc42 participation in the regulation of stimulated PIP2 synthesis. |
| first_indexed | 2024-12-17T07:52:29Z |
| format | Article |
| id | doaj.art-222d59edf07a4870b7397dd4b82d11f1 |
| institution | Directory Open Access Journal |
| issn | 2046-6390 |
| language | English |
| last_indexed | 2024-12-17T07:52:29Z |
| publishDate | 2014-07-01 |
| publisher | The Company of Biologists |
| record_format | Article |
| series | Biology Open |
| spelling | doaj.art-222d59edf07a4870b7397dd4b82d11f12022-12-21T21:57:49ZengThe Company of BiologistsBiology Open2046-63902014-07-013870071010.1242/bio.2014886220148862Activation of Cdc42 is necessary for sustained oscillations of Ca2+ and PIP2 stimulated by antigen in RBL mast cellsMarcus M. WilkesJoshua D. WilsonBarbara BairdDavid HolowkaAntigen stimulation of mast cells via FcεRI, the high-affinity receptor for IgE, triggers a signaling cascade that requires Ca2+ mobilization for exocytosis of secretory granules during the allergic response. To characterize the role of Rho GTPases in FcεRI signaling, we utilized a mutant RBL cell line, B6A4C1, that is deficient in antigen-stimulated Cdc42 activation important for these processes. Recently the importance of stimulated intracellular oscillations has emerged, and we find that B6A4C1 cells exhibit severely attenuated Ca2+ oscillations in response to antigen, which are restored to wild-type RBL-2H3 levels by expression of constitutively active Cdc42 G12V or by a GEF for Cdc42, DOCK7, but not when the C-terminal di-arginine motif of active Cdc42 is mutated to di-glutamine. We found that antigen-stimulated FcεRI endocytosis, which occurs independently of Ca2+ mobilization, is also defective in B6A4C1 cells, and Cdc42 G12V reconstitutes this response as well. Thus, activation of Cdc42 occurs prior to and is critical for antigen-stimulated pathways leading separately to both Ca2+ mobilization and receptor endocytosis. Accounting for these downstream functional consequences, we show that Cdc42 G12V reconstitutes antigen-stimulated oscillations of phosphatidylinositol 4,5-bisphosphate (PIP2) at the plasma membrane in mutant B6A4C1 cells, pointing to Cdc42 participation in the regulation of stimulated PIP2 synthesis.http://bio.biologists.org/content/3/8/700Rho family proteinsFcεRICa2+ signaling |
| spellingShingle | Marcus M. Wilkes Joshua D. Wilson Barbara Baird David Holowka Activation of Cdc42 is necessary for sustained oscillations of Ca2+ and PIP2 stimulated by antigen in RBL mast cells Biology Open Rho family proteins FcεRI Ca2+ signaling |
| title | Activation of Cdc42 is necessary for sustained oscillations of Ca2+ and PIP2 stimulated by antigen in RBL mast cells |
| title_full | Activation of Cdc42 is necessary for sustained oscillations of Ca2+ and PIP2 stimulated by antigen in RBL mast cells |
| title_fullStr | Activation of Cdc42 is necessary for sustained oscillations of Ca2+ and PIP2 stimulated by antigen in RBL mast cells |
| title_full_unstemmed | Activation of Cdc42 is necessary for sustained oscillations of Ca2+ and PIP2 stimulated by antigen in RBL mast cells |
| title_short | Activation of Cdc42 is necessary for sustained oscillations of Ca2+ and PIP2 stimulated by antigen in RBL mast cells |
| title_sort | activation of cdc42 is necessary for sustained oscillations of ca2 and pip2 stimulated by antigen in rbl mast cells |
| topic | Rho family proteins FcεRI Ca2+ signaling |
| url | http://bio.biologists.org/content/3/8/700 |
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