Live cell fluorescence imaging of T cell MEKK2: redistribution and activation in response to antigen stimulation of the T cell receptor.
T cell activation requires engagement of the T cell receptor (TCR) at the interface of conjugates formed with antigen-presenting cells. TCR engagement is accompanied by a redistribution of specific signaling molecules to the cytoplasmic region of the TCR complex. In this study, immunocytochemistry and live cell fluorescence imaging demonstrate that T cell MEK kinase 2 (MEKK2) is translocated to the T cell/antigen-presenting cell interface in response to antigen activation. MEKK2 translocation occurs more rapidly as the antigen concentration is increased. Biochemical activation of MEKK2 follows TCR stimulation, and expression of a dominant-negative MEKK2 inhibits TCR-mediated conjugate stabilization and ERK and p38 MAP kinase phosphorylation. Live cell fluorescence imaging thus enables characterization of signal transducers that are dynamically translocated following TCR engagement.
Schaefer
B C
BC
Howard Hughes Medical Institute and Department of Medicine, National Jewish Medical and Research Center, Denver, Colorado 80206, USA. schaeferb@njc.org
Ware
M F
MF
Marrack
P
P
Fanger
G R
GR
Kappler
J W
JW
Johnson
G L
GL
Monks
C R
CR
D000730:Androstadienes / Q000494:pharmacology; D000818:Animals; D017951:Antigen Presentation; D001692:Biological Transport; D002448:Cell Adhesion; D002460:Cell Line; D004306:Dose-Response Relationship, Immunologic; D004789:Enzyme Activation; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005799:Genes, Dominant; D049452:Green Fluorescent Proteins; D048031:JNK Mitogen-Activated Protein Kinases; D008164:Luminescent Proteins / Q000378:metabolism; D008213:Lymphocyte Activation; D016169:Lymphocyte Function-Associated Antigen-1 / Q000378:metabolism; D048730:MAP Kinase Kinase Kinase 2; D020930:MAP Kinase Kinase Kinases / Q000235:genetics / Q000378:metabolism*; D020935:MAP Kinase Signaling System; D051379:Mice; D008856:Microscopy, Fluorescence; D019950:Mitogen-Activated Protein Kinase 1 / Q000378:metabolism; D048052:Mitogen-Activated Protein Kinase 3; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism; D019869:Phosphatidylinositol 3-Kinases / Q000502:physiology; D000081082:Phosphoinositide-3 Kinase Inhibitors; D010766:Phosphorylation; D011499:Protein Processing, Post-Translational; D011948:Receptors, Antigen, T-Cell / Q000276:immunology*; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D013601:T-Lymphocytes / Q000201:enzymology* / Q000276:immunology / Q000648:ultrastructure; D014162:Transfection; D000077191:Wortmannin; D048051:p38 Mitogen-Activated Protein Kinases
D000730:Androstadienes; D004791:Enzyme Inhibitors; D049452:Green Fluorescent Proteins; D048031:JNK Mitogen-Activated Protein Kinases; D008164:Luminescent Proteins; D016169:Lymphocyte Function-Associated Antigen-1; D048730:MAP Kinase Kinase Kinase 2; D020930:MAP Kinase Kinase Kinases; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3; D020928:Mitogen-Activated Protein Kinases; D019869:Phosphatidylinositol 3-Kinases; D000081082:Phosphoinositide-3 Kinase Inhibitors; D011948:Receptors, Antigen, T-Cell; D011993:Recombinant Fusion Proteins; D000077191:Wortmannin; D048051:p38 Mitogen-Activated Protein Kinases; C482619:Map3k2 protein, mouse