Abstract
Receptor-regulated cellular signaling often is mediated by formation of transient, heterogeneous protein complexes of undefined structure. We used single and two-color photoactivated localization microscopy to study complexes downstream of the T cell antigen receptor (TCR) in single-molecule detail at the plasma membrane of intact T cells. The kinase ZAP-70 distributed completely with the TCRζ chain and both partially mixed with the adaptor LAT in activated cells, thus showing localized activation of LAT by TCR-coupled ZAP-70. In resting and activated cells, LAT primarily resided in nanoscale clusters as small as dimers whose formation depended on protein-protein and protein-lipid interactions. Surprisingly, the adaptor SLP-76 localized to the periphery of LAT clusters. This nanoscale structure depended on polymerized actin and its disruption affected TCR-dependent cell function. These results extend our understanding of the mechanism of T cell activation and the formation and organization of TCR-mediated signaling complexes, findings also relevant to other receptor systems.
| Original language | English |
|---|---|
| Pages (from-to) | 705-720 |
| Number of pages | 16 |
| Journal | Immunity |
| Volume | 35 |
| Issue number | 5 |
| DOIs | |
| State | Published - 23 Nov 2011 |
| Externally published | Yes |
Bibliographical note
Funding Information:The authors would like to thank B.J. Taylor at the NCI Flow Cytometry Core Facility, Zeiss, H. Hess (HHMI, Janelia Farm) for providing the PALM software, W. Losert (University of Maryland) for multiple discussions on data analyses, and T. Wiegand (Helmholtz Centre for Environmental Research—UFZ) for providing us his point-pattern analyses software. We thank P. Sengupta, M. Renz, and T. Jovanovic-Talisman (NIH/NICHD) for reading the manuscript. This research was supported by the Intramural Research Programs of the National Cancer Institute (The Center for Cancer Research) and of the Eunice Kennedy Shriver National Institute of Child Health and Human Development.
