One Lyn molecule is sufficient to initiate phosphorylation of aggregated high-affinity IgE receptors

AUTOR(ES)

Wofsy, Carla

FONTE

The National Academy of Sciences

RESUMO

In response to antigenic stimuli, the multisubunit immune recognition receptors become aggregated and then phosphorylated on their cytoplasmic tyrosines. For the clonotypic receptors of B and T cells and for Fc receptors such as the high-affinity receptor for IgE (FcɛRI), a Src family kinase initiates this phosphorylation. We ask whether aggregation of the initiating kinase itself is required for signal transduction or whether, alternatively, a single associated kinase molecule can phosphorylate the receptors in an aggregate. We formulate the alternative molecular mechanisms mathematically and compare predictions with experimental findings on FcɛRI-bearing cells expressing varying amounts of the transfected Src family kinase Lyn. The data are consistent with the requirement of only a single Lyn molecule per FcɛRI aggregate to initiate signaling and are inconsistent with a mechanism requiring more than one Lyn molecule.

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