Lymphocyte stimulation: concanavalin A induces the expression of a 53K protein

When non-dividing T lymphocytes are treated with concanavalin A in vitro they are stimulated to undergo DNA synthesis and mitotic division. This stimulation is dependent upon the expression of inducible genes. We have now detected a protein that is newly expressed in mouse lymphocytes following mitogenic stimulation. This protein has an apparent molecular weight of 53,000 daltons and may be related to the 53,000 dalton protein that is synthesised constitutively in embryonal carcinoma cells and in SV40 - transformed cells in which it binds to SV40 large-T antigen.