Rescue of signaling by a chimeric protein containing the cytoplasmic domain of CD45.
Surface expression of the CD45 tyrosine phosphatase is essential for the T cell antigen receptor (TCR) to couple optimally with its second messenger pathways. CD45 may be required to dephosphorylate a TCR-activated protein tyrosine kinase, which then transduces an activation signal from the TCR. A chimeric molecule that contained extracellular and transmembrane sequences from an allele of a major histocompatibility class I molecule and cytoplasmic sequences of CD45 restored TCR signaling in a CD45-deficient mutant T cell line. Thus, expression of the complex extracellular domain of CD45 is not required for the TCR to couple to its signaling machinery.
Hovis
R R
RR
Department of Internal Medicine, University of Iowa College of Medicine, Iowa City 52242.
Donovan
J A
JA
Musci
M A
MA
Motto
D G
DG
Goldman
F D
FD
Ross
S E
SE
Koretzky
G A
GA
D001483:Base Sequence; D002460:Cell Line; D002462:Cell Membrane / Q000378:metabolism; D003593:Cytoplasm / Q000378:metabolism; D004789:Enzyme Activation; D006801:Humans; D007295:Inositol Phosphates / Q000378:metabolism; D017493:Leukocyte Common Antigens / Q000235:genetics / Q000378:metabolism*; D008565:Membrane Proteins / Q000378:metabolism; D008969:Molecular Sequence Data; D010766:Phosphorylation; D011505:Protein-Tyrosine Kinases / Q000378:metabolism; D011948:Receptors, Antigen, T-Cell / Q000378:metabolism*; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D015290:Second Messenger Systems; D015398:Signal Transduction; D013601:T-Lymphocytes / Q000378:metabolism*; D014162:Transfection; D014443:Tyrosine / Q000378:metabolism
D007295:Inositol Phosphates; D008565:Membrane Proteins; D011948:Receptors, Antigen, T-Cell; D011993:Recombinant Fusion Proteins; D014443:Tyrosine; D011505:Protein-Tyrosine Kinases; D017493:Leukocyte Common Antigens