Figure 1.

In the immunoglobulin E (IgE)^KVKΔtail mouse strain, the intracellular domain of IgE was removed except for the three conserved amino acids (Lys, Val, Lys). Thus, the cytoplasmic domain of IgE in these mice is identical to the cytoplasmic tail expressed by mIgM and mIgD. In the IgE^ΔM1M2 line, both the intracellular and transmembrane domains of IgE are lacking. The cytoplasmic tails of the membrane immunoglobulins have the capacity to bind proteins, committing a signal transduction pathway which is independent of the well-known Ig-α/Ig-β pathways. The green domains represent Ig heavy chains, red domains indicate Ig light chains, white domain indicates transmembrane domain, clewed domain indicates intracellular tail and pink and brown domains indicate Ig coat proteins Ig-α/Ig-β.