Regulation of human FcεRI β chain gene expression by Oct-1

The β chain, a component of the high-affinity receptor for IgE (FcεRI), plays an important role in IgE-mediated allergic reaction. The β chain accelerates the function of FcεRI by amplification of its surface expression and of signal transduction in effector cells such as mast cells and basophils. Two regulatory regions, +60/+66 and +70/+76, for the human β chain gene that are required for the cell-type-specific transcriptional activation were identified by transient reporter assay. Electrophoretic mobility shift assay demonstrated that Oct-1 binds both the regions, among which the +70/+76 Oct-1 motif was critical for the transactivation of the β promoter responsive to Oct-1 overexpression. Regulation of β chain gene expression is discussed.