Figure 2.

Alignment of IKK-α amino acid sequences with several kinases in the activation loop region. The D(F/L)G and (A/S)PE residues that are characteristic of kinase subdomains VII and VIII are shaded. The conserved threonine and tyrosine residues in the TXXY motif adjacent to subdomain VIII are also shaded. The activating phosphorylation sites in MEK1 (25, 26), MAPK (30), PKA (31), CDK2 (32), and PKC-α (33) are shown in boldface. The position of the serine and threonines residues of IKK-α are indicated. The sequence of the activation loop of IKK-β is also included.