Synergistic assembly of linker for activation of T cells signaling protein complexes in T cell plasma membrane domains.
Transmembrane adaptor molecule LAT (linker for activation of T cells) forms a central scaffold for signaling protein complexes that accumulate in the vicinity of activated T cell antigen receptors (TCR). Here we used biochemical analysis of immunoisolated plasma membrane domains and fluorescence imaging of green fluorescence protein-tagged signaling proteins to investigate the contributions of different tyrosine-based signaling protein docking sites of LAT to the formation of LAT signaling protein assemblies in TCR membrane domains. We found that the phospholipase C gamma docking site of LAT and different Grb2/Gads docking sites function in an interdependent fashion and synergize to accumulate LAT, Grb2, and phospholipase C gamma in TCR signaling assemblies. Two-dimensional gels showed that Grb2 is a predominant cytoplasmic adaptor in the isolated LAT signaling complexes, whereas Gads, Crk-1, and Grap are present in lower amounts. Taken together our data suggest a synergistic assembly of multimolecular TCR.LAT signal transduction complexes in T cell plasma membrane domains.
Hartgroves
Lorian C
LC
Sir William Dunn School of Pathology, University of Oxford, South Parks Road, United Kingdom.
Lin
Joseph
J
Langen
Hanno
H
Zech
Tobias
T
Weiss
Arthur
A
Harder
Thomas
T
D048868:Adaptor Proteins, Signal Transducing; D001665:Binding Sites; D002352:Carrier Proteins / Q000378:metabolism*; D002462:Cell Membrane / Q000378:metabolism; D015180:Electrophoresis, Gel, Two-Dimensional; D051380:GRB2 Adaptor Protein; D049452:Green Fluorescent Proteins; D006801:Humans; D019169:Jurkat Cells; D008164:Luminescent Proteins / Q000378:metabolism; D008565:Membrane Proteins; D008856:Microscopy, Fluorescence; D051966:Phospholipase C gamma; D010750:Phosphoproteins / Q000378:metabolism*; D011506:Proteins / Q000378:metabolism; D011948:Receptors, Antigen, T-Cell / Q000378:metabolism; D013601:T-Lymphocytes / Q000378:metabolism*; D010738:Type C Phospholipases / Q000378:metabolism; D018909:src Homology Domains
D048868:Adaptor Proteins, Signal Transducing; D002352:Carrier Proteins; D051380:GRB2 Adaptor Protein; C495948:GRB2 protein, human; C110810:LAT protein, human; D008164:Luminescent Proteins; D008565:Membrane Proteins; D010750:Phosphoproteins; D011506:Proteins; D011948:Receptors, Antigen, T-Cell; D049452:Green Fluorescent Proteins; D010738:Type C Phospholipases; D051966:Phospholipase C gamma