In:
Proceedings of the National Academy of Sciences, Proceedings of the National Academy of Sciences, Vol. 100, No. 16 ( 2003-08-05), p. 9434-9439
Abstract:
Previous studies have demonstrated that the specificity of Src homology 2
(SH2) and phosphotyrosine-binding domain interactions are mediated by phosphorylated tyrosines and their neighboring amino acids. Two of the first
phosphotyrosine-based binding sites were found on middle T antigen of polyoma virus. Tyr-250 acts as a binding site for ShcA, whereas Tyr-315 forms a
binding site for the SH2 domain of the p85 subunit of phosphatidylinositol 3-kinase. However, genetic analysis of a given phosphotyrosine's role in
signaling can be complicated when it serves as a binding site for multiple proteins. The situation is particularly difficult when the phosphotyrosine
serves as a secondary binding site for a protein with primary binding determinates elsewhere. Mutation of a tyrosine residue to phenylalanine blocks
association of all bound proteins. Here we show that the mutation of the amino acids following the phosphorylated tyrosine to alanine can reveal
phosphotyrosine function as a secondary binding site, while abrogating the phosphotyrosine motif's role as a primary binding site for SH2 domains. We
tested this methodology by using middle T antigen. Our results suggest that Tyr-250 is a secondary binding site for phosphatidylinositol 3-kinase, whereas
Tyr-315 is a secondary binding site for a yet-to-be-identified protein, which is critical for transformation.
Type of Medium:
Online Resource
ISSN:
0027-8424
,
1091-6490
DOI:
10.1073/pnas.1432964100
Language:
English
Publisher:
Proceedings of the National Academy of Sciences
Publication Date:
2003
detail.hit.zdb_id:
209104-5
detail.hit.zdb_id:
1461794-8
SSG:
11
SSG:
12
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