Single-molecule microscopy reveals heterogeneous dynamics of lipid raft components upon TCR engagement.
The existence of lipid rafts and their importance for immunoreceptor signaling is highly debated. By non-invasive single molecule imaging, we analyzed the dynamics of the T-cell antigen receptor (TCR), the lipid raft-associated glycosylphosphatidylinositol (GPI) proteins CD48 and CD59 and the major leukocyte phosphatase CD45 in living naive T lymphocytes. TCR triggering induced the immobilization of CD45 and CD48 at different positions within the T-cell interface. The second GPI protein, CD59, did not co-immobilize indicating lipid raft heterogeneity in living T lymphocytes. A novel biochemical approach confirmed that lipid raft components are not associated in the plasma membrane of resting cells, and variably associate with specific receptors to distinct lipid rafts upon activation.
Drbal
Karel
K
Competence Centre for Biomolecular Therapeutics Research Vienna, A-1090, Vienna.
Moertelmaier
Manuel
M
Holzhauser
Christa
C
Muhammad
Arshad
A
Fuertbauer
Elke
E
Howorka
Stefan
S
Hinterberger
Maria
M
Stockinger
Hannes
H
Schütz
Gerhard J
GJ
D015703:Antigens, CD / Q000378:metabolism / Q000648:ultrastructure; D017252:CD3 Complex / Q000378:metabolism / Q000648:ultrastructure; D000071178:CD48 Antigen; D018957:CD59 Antigens / Q000378:metabolism / Q000648:ultrastructure; D002462:Cell Membrane / Q000737:chemistry / Q000648:ultrastructure; D017261:Glycosylphosphatidylinositols / Q000737:chemistry; D006801:Humans; D007700:Kinetics; D017493:Leukocyte Common Antigens / Q000378:metabolism / Q000648:ultrastructure; D008213:Lymphocyte Activation; D008563:Membrane Lipids / Q000737:chemistry / Q000378:metabolism; D021962:Membrane Microdomains / Q000378:metabolism* / Q000648:ultrastructure*; D018613:Microscopy, Confocal; D009038:Motion; D011485:Protein Binding / Q000276:immunology; D011948:Receptors, Antigen, T-Cell / Q000737:chemistry / Q000378:metabolism / Q000648:ultrastructure*; D013601:T-Lymphocytes / Q000276:immunology* / Q000378:metabolism / Q000648:ultrastructure
D015703:Antigens, CD; D017252:CD3 Complex; D000071178:CD48 Antigen; C000604065:CD48 protein, human; D018957:CD59 Antigens; D017261:Glycosylphosphatidylinositols; D008563:Membrane Lipids; D011948:Receptors, Antigen, T-Cell; D017493:Leukocyte Common Antigens