The T cell receptor triggering apparatus is composed of monovalent or monomeric proteins
| Autor: | John R. James, Simon J. Davis, David Klenerman, Andreas Jansson, Ricardo A. Fernandes, Patric Nilsson, Sara H. Morgan, Marta I. Oliveira, Carine M. Gonçalves, David L. Sleep, Paul Dunne, Robert Mahen, Alexandre M. Carmo, James McColl, James H. Felce, Elizabeth Huang |
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| Jazyk: | angličtina |
| Rok vydání: | 2016 |
| Předmět: |
Protein Structure
Protein Stoichiometry T-Lymphocytes T cell Immunology Bioluminescence Resonance Energy Transfer chemical and pharmacologic phenomena Major histocompatibility complex Biochemistry Jurkat cells Cell membrane Jurkat Cells 03 medical and health sciences Cytosol HLA Antigens Receptors Single Molecule Biophysics medicine Humans Molecular Biology 030304 developmental biology 0303 health sciences biology Cell Membrane 030302 biochemistry & molecular biology T-cell receptor Models Immunological Membrane Proteins Fluorescence recovery after photobleaching hemic and immune systems Cell Biology Cell biology Receptors Antigen HEK293 Cells T Cell Receptor medicine.anatomical_structure Membrane protein Lymphocyte Specific Protein Tyrosine Kinase p56(lck) Cytoplasm CD4 Antigens Cell Surface biology.protein Leukocyte Common Antigens Signal Transduction |
| Zdroj: | The Journal of Biological Chemistry |
| Popis: | Understanding the component stoichiometry of the T cell antigen receptor (TCR) triggering apparatus is essential for building realistic models of signal initiation. Recent studies suggesting that the TCR and other signaling-associated proteins are preclustered on resting T cells relied on measurements of the behavior of membrane proteins at interfaces with functionalized glass surfaces. Using fluorescence recovery after photobleaching, we show that, compared with the apical surface, the mobility of TCRs is significantly reduced at Jurkat T cell/glass interfaces, in a signaling-sensitive manner. Using two biophysical approaches that mitigate these effects, bioluminescence resonance energy transfer and two-color coincidence detection microscopy, we show that, within the uncertainty of the methods, the membrane components of the TCR triggering apparatus, i.e. the TCR complex, MHC molecules, CD4/Lck and CD45, are exclusively monovalent or monomeric in human T cell lines, implying that TCR triggering depends only on the kinetics of TCR/pMHC interactions. These analyses also showed that constraining proteins to two dimensions at the cell surface greatly enhances random interactions versus those between the membrane and the cytoplasm. Simulations of TCR-pMHC complex formation based on these findings suggest how unclustered TCR triggering-associated proteins might nevertheless be capable of generating complex signaling outputs via the differential recruitment of cytosolic effectors to the cell membrane. |
| Databáze: | OpenAIRE |
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