Thy-1 functions as a signal transduction molecule in T lymphocytes and transfected B lymphocytes.
Thy-1, a glycoprotein of relative molecular mass 25,000 (25K), is a major constituent of the cell surface of mouse thymocytes, peripheral T cells and neurones. In man, Thy-1 is present on neurones and on a small percentage of thymocytes, but is absent from peripheral T cells. The amino-acid and complementary DNA sequences of Thy-1 indicate that it has a structure similar to an isolated V (variable region) domain of immunoglobulin. Although the function of Thy-1 is unknown, the ability of different anti-Thy-1 monoclonal antibodies to activate murine T cells or induce functional changes in neuronal cells in vitro suggests that Thy-1 is involved in transmembrane signalling. We now show that crosslinking of murine Thy-1 triggers a rapid rise in the cytoplasmic free calcium concentration ([Ca2+]i), not only in murine T cells and Thy-1.2-transfected human T cells, but also in murine B-lymphoma cells transfected with the murine thy-1.2 gene. These results indicate that the generation and transduction of the signal leading to the rise in [Ca2+]i is independent of the T-cell receptor and other T-cell-specific molecules. The preservation of the [Ca2+]i-modulating function of Thy-1 in various lymphoid cells of two species further suggests that the necessary signal either originates in the Thy-1 molecule itself or is generated in concert with a highly conserved molecules(s) associated with Thy-1.
Kroczek
R A
RA
Gunter
K C
KC
Germain
R N
RN
Shevach
E M
EM
D000818:Animals; D000911:Antibodies, Monoclonal; D000954:Antigens, Surface / Q000502:physiology*; D001402:B-Lymphocytes / Q000502:physiology*; D002118:Calcium / Q000378:metabolism; D002450:Cell Communication; D002460:Cell Line; D006801:Humans; D008213:Lymphocyte Activation; D051379:Mice; D013601:T-Lymphocytes / Q000378:metabolism / Q000502:physiology*; D018800:Thy-1 Antigens; D014162:Transfection
D000911:Antibodies, Monoclonal; D000954:Antigens, Surface; D018800:Thy-1 Antigens; D002118:Calcium