Proteomic analysis of secretagogue-stimulated neutrophils implicates a role for actin and actin-interacting proteins in Rac2-mediated granule exocytosis
<p>Abstract</p> <p>Background</p> <p>Neutrophils are abundant leukocytes that play a primary role in defence against pathogens. Neutrophils enter sites of infection where they eliminate pathogens via phagocytosis and the release of antimicrobial mediators via degranulat...
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| Format: | Article |
| Language: | English |
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BMC
2011-11-01
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| Series: | Proteome Science |
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| Online Access: | http://www.proteomesci.com/content/9/1/70 |
| _version_ | 1811284495337259008 |
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| author | Eitzen Gary Lo Andrea N Mitchell Troy Kim John D Chao Danny V Lacy Paige |
| author_facet | Eitzen Gary Lo Andrea N Mitchell Troy Kim John D Chao Danny V Lacy Paige |
| author_sort | Eitzen Gary |
| collection | DOAJ |
| description | <p>Abstract</p> <p>Background</p> <p>Neutrophils are abundant leukocytes that play a primary role in defence against pathogens. Neutrophils enter sites of infection where they eliminate pathogens via phagocytosis and the release of antimicrobial mediators via degranulation. Rho GTPases, particularly Rac2, play a key role in neutrophil degranulation. The purpose of this study was to identify Rac2-dependent changes in protein abundance in stimulated neutrophils.</p> <p>Methods</p> <p>We performed a proteomic analysis on secretagogue-stimulated bone marrow neutrophils that were isolated from wild-type and Rac2<sup>-/- </sup>mice. Protein abundance was analyzed by 2-dimensional SDS-PAGE of fluorescently labelled samples which allowed the detection ~3500 proteins.</p> <p>Results</p> <p>We identified 22 proteins that showed significant changes in abundance after secretagogue-stimulation of wild-type neutrophils, which did not occur in neutrophils isolated from Rac2<sup>-/- </sup>mice. As expected, the abundance of several granule proteins was reduced in wild-type cells; this did not occur in Rac2<sup>-/- </sup>neutrophils which confirms the requirement for Rac2 in degranulation. We also found changes in abundance of many actin remodelling proteins including coronin-1A, β-actin and the F-actin capping protein, (CapZ-β). Coronin-1A showed elevated levels of several isoforms after stimulation of neutrophils from wild-type, but not from Rac2<sup>-/- </sup>mice. These isoforms were immunoreactive with anti-phospho-threonine antibodies, suggesting that neutrophil stimulation triggers a Rac2-dependent kinase cascade that results in the phosphorylation of coronin-1A.</p> <p>Conclusion</p> <p>The control of Rac2-mediated degranulation in neutrophils likely functions through actin remodelling via activation of several actin-binding proteins. We found coronin-1A to be a novel downstream effector protein of this pathway that is threonine phosphorylated in response to secretagogue stimulation.</p> |
| first_indexed | 2024-04-13T02:30:20Z |
| format | Article |
| id | doaj.art-87fc86f2c05343a59927ffb64665b203 |
| institution | Directory Open Access Journal |
| issn | 1477-5956 |
| language | English |
| last_indexed | 2024-04-13T02:30:20Z |
| publishDate | 2011-11-01 |
| publisher | BMC |
| record_format | Article |
| series | Proteome Science |
| spelling | doaj.art-87fc86f2c05343a59927ffb64665b2032022-12-22T03:06:37ZengBMCProteome Science1477-59562011-11-01917010.1186/1477-5956-9-70Proteomic analysis of secretagogue-stimulated neutrophils implicates a role for actin and actin-interacting proteins in Rac2-mediated granule exocytosisEitzen GaryLo Andrea NMitchell TroyKim John DChao Danny VLacy Paige<p>Abstract</p> <p>Background</p> <p>Neutrophils are abundant leukocytes that play a primary role in defence against pathogens. Neutrophils enter sites of infection where they eliminate pathogens via phagocytosis and the release of antimicrobial mediators via degranulation. Rho GTPases, particularly Rac2, play a key role in neutrophil degranulation. The purpose of this study was to identify Rac2-dependent changes in protein abundance in stimulated neutrophils.</p> <p>Methods</p> <p>We performed a proteomic analysis on secretagogue-stimulated bone marrow neutrophils that were isolated from wild-type and Rac2<sup>-/- </sup>mice. Protein abundance was analyzed by 2-dimensional SDS-PAGE of fluorescently labelled samples which allowed the detection ~3500 proteins.</p> <p>Results</p> <p>We identified 22 proteins that showed significant changes in abundance after secretagogue-stimulation of wild-type neutrophils, which did not occur in neutrophils isolated from Rac2<sup>-/- </sup>mice. As expected, the abundance of several granule proteins was reduced in wild-type cells; this did not occur in Rac2<sup>-/- </sup>neutrophils which confirms the requirement for Rac2 in degranulation. We also found changes in abundance of many actin remodelling proteins including coronin-1A, β-actin and the F-actin capping protein, (CapZ-β). Coronin-1A showed elevated levels of several isoforms after stimulation of neutrophils from wild-type, but not from Rac2<sup>-/- </sup>mice. These isoforms were immunoreactive with anti-phospho-threonine antibodies, suggesting that neutrophil stimulation triggers a Rac2-dependent kinase cascade that results in the phosphorylation of coronin-1A.</p> <p>Conclusion</p> <p>The control of Rac2-mediated degranulation in neutrophils likely functions through actin remodelling via activation of several actin-binding proteins. We found coronin-1A to be a novel downstream effector protein of this pathway that is threonine phosphorylated in response to secretagogue stimulation.</p>http://www.proteomesci.com/content/9/1/70neutrophildegranulationexocytosisRac2GTPaseactincoronin |
| spellingShingle | Eitzen Gary Lo Andrea N Mitchell Troy Kim John D Chao Danny V Lacy Paige Proteomic analysis of secretagogue-stimulated neutrophils implicates a role for actin and actin-interacting proteins in Rac2-mediated granule exocytosis Proteome Science neutrophil degranulation exocytosis Rac2 GTPase actin coronin |
| title | Proteomic analysis of secretagogue-stimulated neutrophils implicates a role for actin and actin-interacting proteins in Rac2-mediated granule exocytosis |
| title_full | Proteomic analysis of secretagogue-stimulated neutrophils implicates a role for actin and actin-interacting proteins in Rac2-mediated granule exocytosis |
| title_fullStr | Proteomic analysis of secretagogue-stimulated neutrophils implicates a role for actin and actin-interacting proteins in Rac2-mediated granule exocytosis |
| title_full_unstemmed | Proteomic analysis of secretagogue-stimulated neutrophils implicates a role for actin and actin-interacting proteins in Rac2-mediated granule exocytosis |
| title_short | Proteomic analysis of secretagogue-stimulated neutrophils implicates a role for actin and actin-interacting proteins in Rac2-mediated granule exocytosis |
| title_sort | proteomic analysis of secretagogue stimulated neutrophils implicates a role for actin and actin interacting proteins in rac2 mediated granule exocytosis |
| topic | neutrophil degranulation exocytosis Rac2 GTPase actin coronin |
| url | http://www.proteomesci.com/content/9/1/70 |
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