The death domain kinase RIP1 is essential for tumor necrosis factor alpha signaling to p38 mitogen-activated protein kinase
Graduate School of Biomedical Sciences; Department of Cancer Biology and Interdisciplinary Graduate Program; Program in Molecular Medicine and Howard Hughes Medical Institute; Program in Gene Function and Expression
Life Sciences | Medicine and Health Sciences
The cytokine tumor necrosis factor alpha (TNF-alpha) stimulates the NF-kappaB, SAPK/JNK, and p38 mitogen-activated protein (MAP) kinase pathways by recruiting RIP1 and TRAF2 proteins to the tumor necrosis factor receptor 1 (TNFR1). Genetic studies have revealed that RIP1 links the TNFR1 to the IkappaB kinase (IKK) complex, whereas TRAF2 couples the TNFR1 to the SAPK/JNK cascade. In transfection studies, RIP1 and TRAF2 stimulate p38 MAP kinase activation, and dominant-negative forms of RIP1 and TRAF2 inhibit TNF-alpha-induced p38 MAP kinase activation. We found TNF-alpha-induced p38 MAP kinase activation and interleukin-6 (IL-6) production impaired in rip1(-/-) murine embryonic fibroblasts (MEF) but unaffected in traf2(-/-) MEF. Yet, both rip1(-/-) and traf2(-/-) MEF exhibit a normal p38 MAP kinase response to inducers of osmotic shock or IL-1alpha. Thus, RIP1 is a specific mediator of the p38 MAP kinase response to TNF-alpha. These studies suggest that TNF-alpha-induced activation of p38 MAP kinase and SAPK/JNK pathways bifurcate at the level of RIP1 and TRAF2. Moreover, endogenous RIP1 associates with the MAP kinase kinase kinase (MAP3K) MEKK3 in TNF-alpha-treated cells, and decreased TNF-alpha-induced p38 MAP kinase activation is observed in Mekk3(-/-) cells. Taken together, these studies suggest a mechanism whereby RIP1 may mediate the p38 MAP kinase response to TNF-alpha, by recruiting the MAP3K MEKK3.
Mol Cell Biol. 2003 Nov;23(22):8377-85.
Molecular and cellular biology
Lee, Thomas H.; Huang, Qiaojia; Oikemus, Sarah R.; Shank, Jennifer; Ventura, Juan-Jose; Cusson, Nicole; Vaillancourt, Richard R.; Su, Bing; Davis, Roger J.; and Kelliher, Michelle, "The death domain kinase RIP1 is essential for tumor necrosis factor alpha signaling to p38 mitogen-activated protein kinase" (2003). GSBS Student Publications. 669.