Helicobacter pylori, the etiological agent of several human gastric diseases, 
induces the transcription factor nuclear factor-κB (NF-κB) in colonized 
epithelial cells leading to the release of proinflammatory mediators. Activation 
of NF-κB involves the IκB kinase (IKK)-complex composed of two catalytic 
subunits, IKKα and IKKβ, and a regulatory scaffold protein, IKKγ. IKKβ was shown 
to be essential for NF-κB activation in response to a variety of stimuli 
including H. pylori. In addition to the phosphorylation of serine residues, 
tyrosine phosphorylation could be crucial for IKKβ activation. Here we provide 
evidence that IKKβ phosphorylation is induced in lipid rafts (DRM fractions) of 
H. pylori-infected cells, but not TNFα-stimulated cells. Furthermore, H. pylori 
transiently induces binding of IKKβ to c-Src kinase. Inhibition of c-Src by 
specific inhibitors as well as knockdown of c-Src by small interfering RNA 
reduced phosphorylation of IκBα as well as of p65. Thus, tyrosine-phosphorylated 
IKKβ contributes at least in part to NF-κB activation in response to H. pylori 
infection.