Ezrin and moesin function together to promote T cell activation.
Publication/Presentation Date
1-15-2009
Abstract
The highly homologous proteins ezrin, radixin, and moesin link proteins to the actin cytoskeleton. The two family members expressed in T cells, ezrin and moesin, are implicated in promoting T cell activation and polarity. To elucidate the contributions of ezrin and moesin, we conducted a systematic analysis of their function during T cell activation. In response to TCR engagement, ezrin and moesin were phosphorylated in parallel at the regulatory threonine, and both proteins ultimately localized to the distal pole complex (DPC). However, ezrin exhibited unique behaviors, including tyrosine phosphorylation and transient localization to the immunological synapse before movement to the DPC. To ask whether these differences reflect unique requirements for ezrin vs moesin in T cell signaling, we generated mice with conditional deletion of ezrin in mature T cells. Ezrin-/- T cells exhibited normal immunological synapse organization based upon localization of protein kinase C-theta, talin, and phospho-ZAP70. DPC localization of CD43 and RhoGDP dissociation inhibitor, as well as the novel DPC protein Src homology region 2 domain-containing phosphatase-1, was also unaffected. However, recruitment of three novel DPC proteins, ezrin binding protein of 50 kDa, Csk binding protein, and the p85 subunit of PI3K was partially perturbed. Biochemical analysis of ezrin-/- T cells or T cells suppressed for moesin using small interfering RNA showed intact early TCR signaling, but diminished levels of IL-2. The defects in IL-2 production were more pronounced in T cells deficient for both ezrin and moesin. These cells also exhibited diminished phospholipase C-gamma1 phosphorylation and calcium flux. We conclude that despite their unique movement and phosphorylation patterns, ezrin and moesin function together to promote T cell activation.
Volume
182
Issue
2
First Page
1021
Last Page
1032
ISSN
1550-6606
Published In/Presented At
Shaffer, M. H., Dupree, R. S., Zhu, P., Saotome, I., Schmidt, R. F., McClatchey, A. I., Freedman, B. D., & Burkhardt, J. K. (2009). Ezrin and moesin function together to promote T cell activation. Journal of immunology (Baltimore, Md. : 1950), 182(2), 1021–1032. https://doi.org/10.4049/jimmunol.182.2.1021
Disciplines
Business Administration, Management, and Operations | Health and Medical Administration | Management Sciences and Quantitative Methods
PubMedID
19124745
Department(s)
Administration and Leadership
Document Type
Article