Regulation of TCR signaling by CD45 lacking transmembrane and extracellular domains.
The CD45 protein is a transmembrane tyrosine phosphatase that is required for normal T cell receptor (TCR)-mediated signaling. A chimeric complementary DNA encoding the intracellular enzymatically active portion of murine CD45 preceded by a short amino-terminal sequence from p60c-src was transfected into CD45- T cells. Expression of this chimeric protein corrected most of the TCR signaling abnormalities observed in the absence of CD45, including TCR-mediated enhancement of tyrosine kinase activity and Ca2+ flux. Thus, the enzymatically active intracellular portion of CD45 is sufficient to allow TCR transmembrane signaling.
Volarević
S
S
Laboratory of Immune Cell Biology, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892.
Niklinska
B B
BB
Burns
C M
CM
June
C H
CH
Weissman
A M
AM
Ashwell
J D
JD
D000818:Animals; D001483:Base Sequence; D017252:CD3 Complex / Q000276:immunology; D002118:Calcium / Q000378:metabolism; D002462:Cell Membrane / Q000378:metabolism; D017493:Leukocyte Common Antigens / Q000235:genetics / Q000378:metabolism*; D008565:Membrane Proteins / Q000378:metabolism; D051379:Mice; 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; D015398:Signal Transduction; D014407:Tumor Cells, Cultured; D014443:Tyrosine / Q000378:metabolism
D017252:CD3 Complex; D008565:Membrane Proteins; D011948:Receptors, Antigen, T-Cell; D011993:Recombinant Fusion Proteins; D014443:Tyrosine; D011505:Protein-Tyrosine Kinases; D017493:Leukocyte Common Antigens; D002118:Calcium