文字方塊: KB.

Ikb

 

 

 
IKB

文字方塊: Ikk
 


     

 

 

                                     PKC

 

 

 

 

 

 

 

 

 

 

 

 

The NF-kappa-B (NFKB) complex of proteins is inhibited by I-kappa-B (IKB) proteins, which inactivate NFKB by trapping it in the cytoplasm. Phosphorylation of serine residues on the IKB proteins by IKB kinases marks them for destruction via the ubiquitination pathway, thereby allowing activation and nuclear translocation of the NFKB complex. The protein encoded by this gene is similar to IKB kinases and can mediate NFKB activation in response to certain growth factors. For example, the protein can form a complex with the IKB protein TANK and TRAF2 and release the NFKB inhibition caused by TANK.

The transcription factor NF-kappaB is implicated in various aspects of T cell development and function. The IkappaB kinase (IKK) complex, consisting of two kinases, IKK1/alpha and IKK2/beta, and the NEMO/IKKgamma regulatory subunit, mediates NF-kappaB activation by most known stimuli. Adoptive transfer experiments had demonstrated that IKK1 and IKK2 are dispensable for T cell development. We show here that T lineage-specific deletion of IKK2 allows survival of naive peripheral T cells but interferes with the generation of regulatory and memory T cells. T cell-specific ablation of NEMO or replacement of IKK2 with a kinase-dead mutant prevent development of peripheral T cells altogether. Thus, IKK-induced NF-kappaB activation, mediated by either IKK1 or IKK2, is essential for the generation and survival of mature T cells, and IKK2 has an additional role in regulatory and memory T cell development.          10/9/03