The serine and threonine residues in the Ig-alpha cytoplasmic tail negatively regulate immunoreceptor tyrosine-based activation motif-mediated signal transduction.
نویسندگان
چکیده
The B cell antigen receptor (BCR) is a multiprotein complex consisting of the membrane-bound Ig molecule and the Ig-alpha/Ig-beta heterodimer. On BCR engagement, Ig-alpha and Ig-beta become phosphorylated not only on tyrosine residues of the immunoreceptor tyrosine-based activation motif but also on serine and threonine residues. We have mutated all serine and threonine residues in the Ig-alpha tail to alanine and valine, respectively. The mutated Ig-alpha sequence was expressed either as a single-chain Fv/Ig-alpha molecule or in the context of the complete BCR. In both cases, the mutated Ig-alpha showed a stronger tyrosine phosphorylation than the wild-type Ig-alpha and initiated increased signaling on stimulation. These findings suggest that serine/threonine kinases can negatively regulate signal transduction from the BCR.
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عنوان ژورنال:
- Proceedings of the National Academy of Sciences of the United States of America
دوره 97 15 شماره
صفحات -
تاریخ انتشار 2000