Fig 1.

Identification of tyrosine phosphorylation sites of CagA and their roles in SHP-2 binding and morphological transformation. (a) The EPIYA motifs present in NCTC11637 CagA (Upper) and schematic view of the EPIYA mutants (Lower). Three repeats of the Western CagA-specific sequence (WSS) are each boxed. All CagA constructs were C-terminal HA-tagged. WT: WT 11637-CagA; PR: phosphorylation-resistant CagA. (b and c) AGS cells were transfected with WT-CagA, each of EPIYA mutant, or a control vector. CagA proteins then were immunoprecipitated from cell lysates with anti-HA. The immunoprecipitates (IP) and total cell lysates (TCL) were immunoblotted (IB) with antibodies as described. (d) AGS cells were transiently transfected with an expression vector for WT or EPIYA mutant of CagA. Cells showing the hummingbird phenotype were counted.