What question did this study set out to answer?

To examine how wortmannin-mediated inhibition of PI 3-kinase alters downstream signaling pathways and cellular responses induced by Fc epsilon R1 cross-linking in mast cells.

September 1, 1995Molecular Biology of the CellOpen Access

Wortmannin blocks lipid and protein kinase activities associated with PI 3-kinase and inhibits a subset of responses induced by Fc epsilon R1 cross-linking.

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Authors

SBSheryll A. BarkerQueen Mary University of London KCKevin K. CaldwellWestinghouse Electric (Germany)AHA L HallUniversity of New Mexico

Discussion

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Implication

In vitro study reveals that wortmannin selectively blocks Fc epsilon R1 signaling and PI 3-kinase activities in mast cells, highlighting distinct pathways in allergic activation.

Key Points

To examine how wortmannin-mediated inhibition of PI 3-kinase alters downstream signaling pathways and cellular responses induced by Fc epsilon R1 cross-linking in mast cells.
Treated RBL-2H3 mast cells with wortmannin prior to or during antigen-induced Fc epsilon R1 activation.
Measured lipid kinase and serine/threonine protein kinase activities in vitro using p85 subunit immunoprecipitates and determined inositol(1,4,5)P3 generation.
Assessed cellular endpoints including degranulation, membrane ruffling, fluid pinocytosis, actin polymerization, cell spreading, and tyrosine kinase activation.
Wortmannin markedly suppressed antigen-stimulated inositol(1,4,5)P3 production, membrane ruffling, and fluid pinocytosis, while also directly inhibiting the newly identified serine/threonine protein kinase activity of PI 3-kinase.
Antigen-induced actin polymerization, receptor internalization, cell spreading, and adhesion plaque formation were completely unaffected by wortmannin treatment.
Upstream tyrosine kinases Lyn and Syk, as well as downstream mitogen-activated protein kinase activation, maintained normal activity despite wortmannin exposure.

Cite This Study

Barker et al. (1995) studied this question.

synapsesocial.com/papers/6a78da3f3057cf3c2e01f7bf https://doi.org/10.1091/mbc.6.9.1145

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Implication

In vitro study reveals that wortmannin selectively blocks Fc epsilon R1 signaling and PI 3-kinase activities in mast cells, highlighting distinct pathways in allergic activation.

Wortmannin blocks lipid and protein kinase activities associated with PI 3-kinase and inhibits a subset of responses induced by Fc epsilon R1 cross-linking.

Discussion

Member takes

Implication

Key Points

Cite This Study

Wortmannin blocks lipid and protein kinase activities associated with PI 3-kinase and inhibits a subset of responses induced by Fc epsilon R1 cross-linking.

Discussion

Member takes

Implication

Key Points

Cite This Study

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