Signal transduction through the conserved motifs of the high affinity IgE receptor Fc epsilon RI

Abstract

The high affinity receptor for IgE, Fc epsilon RI, possesses three ARAMs, one in the beta chain (ARAM-beta) and one in each member of the dimer of gamma chains (ARAM-gamma). These two types of ARAM endow the chains in which they are located with distinct properties. The ARAM-containing C-terminal tail of beta binds Lyn, a Src family tyrosine kinase which regulates the phosphorylation of beta, gamma and other substrates including Syk. The tyrosine phosphorylated ARAM-containing C-terminal tail of gamma binds Syk which, when activated, controls later signals such as the rise in intracellular calcium. Therefore, the two ARAM-containing chains of Fc epsilon RI cooperate to realize the full signaling capacity of the receptor.