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Updated: Sep 27, 2025

Isolation of Peritoneum-derived Mast Cells and Their Functional Characterization with Ca2+-imaging and Degranulation Assays
Published on: July 4, 2018
Dok-1 regulates mast cell degranulation negatively through inhibiting calcium-dependent F-actin disassembly
Hang Du1, Na Sun2, Shiwen Han1
1Key Laboratory of Precision Nutrition and Food Quality, Key Laboratory of Functional Dairy, Ministry of Education, College of Food Science and Nutritional Engineering, China Agricultural University, Beijing 100083, PR China.
Abstract:
In food allergies, antigen-induced aggregation of FcεRI on mast cells initiates highly ordered and sequential signaling events. Dok-1(downstream of tyrosine kinase 1), undergoes intense tyrosine phosphorylation upon FcεRI stimulation, which negatively regulates Ras/Erk signaling and the subsequent cytokine release, but it remains unclear whether Dok-1 regulates Fc-mediated degranulation. In this study, we investigated the role of Dok-1 in FcεRI-mediated degranulation. Dok-1 overexpressing RBL-2H3 cells were established. Degranulation, immunoprecipitation, co-immunoprecipitation, immunoblotting and flow cytometry assay were performed to explore the effects of Dok-1 and its underlying mechanisms. We found that, following FcεRI activation, Dok-1 was recruited to the plasma membrane, leading to tyrosine phosphorylation. Phosphorylated Dok-1 inhibits FcεRI-operated calcium influx, and negatively regulated degranulation by inhibiting calcium-dependent disassembly of actin filaments. Our data revealed that Dok-1 is a negative regulator of FcεRI-mediated mast cell degranulation. These findings contribute to the identification of therapeutic targets for food allergies.
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