Tumour Necrosis Factor and Interleukin-1

SAPKs (and p38 MAPK) are potently activated by these inflammatory cytokines. The two TNF receptors (p55 and p75), CD40 and IL-1 receptor signal via recruitment of associated proteins, termed TRAFs or CRAFs. One of these, TRAF2, activates the SAPKs upon overexpression. TRAF2 also induces NF-kB. However, activation of this transcription factor and SAPK can be functionally and temporally distinguished.