A physical and functional map of the human TNF-α/NF-κB signal transduction pathway

Abstract

Signal transduction pathways are modular composites of functionally interdependent sets of proteins that act in a coordinated fashion to transform environmental information into a phenotypic response. The pro-inflammatory cytokine tumour necrosis factor (TNF)-alpha triggers a signalling cascade, converging on the activation of the transcription factor NF-kappa B, which forms the basis for numerous physiological and pathological processes. Here we report the mapping of a protein interaction network around 32 known and candidate TNF-alpha/NF-kappa B pathway components by using an integrated approach comprising tandem affinity purification, liquid-chromatography tandem mass spectrometry, network analysis and directed functional perturbation studies using RNA interference. We identified 221 molecular associations and 80 previously unknown interactors, including 10 new functional modulators of the pathway. This systems approach provides significant insight into the logic of the TNF-alpha/NF-kappa B pathway and is generally applicable to other pathways relevant to human disease.

Regulation and function of TPL-2, an IκB kinase-regulated MAP kinase kinase kinase

“…Tandem-affinity purification and peptide mass fingerprinting identified A20-binding inhibitor of NF-κB 2 (ABIN-2) as an NF-κB1 p105-interacting protein [56,57]. Cotransfection experiments indicate that ABIN-2 can also interact directly with TPL-2, but preferentially forms a ternary complex with p105 and TPL-2.…”

New insights into the biogenesis of nuclear RNA polymerases?This paper is one of a selection of papers published in this special issue entitled “Canadian Society of Biochemistry, Molecular & Cellular Biology 52nd Annual Meeting — Protein Folding: Principles and Diseases” and has undergone the Journal's usual peer review process.

“…In a landmark report aimed at mapping the entirety of the interaction network of the TNF-α/NF-κB signal transduction pathway by AP-MS, MEKK3 was found in association with the majority of RPAP3/R2TP/prefoldin-like complex subunits (Bouwmeester et al 2004). Indeed, RPAP3 (FLJ21908), PIH1D1 (FLJ20643), RUVBL1, RUVBL2, PFDN2, PFDN6 (HKE2), PDRG1 (C20orf126) and C19orf2 all copurified with MEKK3, as did the CCT complex and Hsp90α/β.…”

Promoter methylation of the mutated in colorectal cancer gene is a frequent early event in colorectal cancer

“…One mutation tested was the same as that initially identified in a tumor from a colorectal cancer patient (Kinzler et al, 1991). Particularly interesting is the finding that MCC appears to stabilize the IkBb protein that is an essential inhibitor of NF-kB transcription factor activation (Bouwmeester et al, 2004). There is evidence that NF-kB activation is involved in colorectal carcinogenesis (Karin et al, 2002) and that it can be caused by the BRAF V600E mutation in vitro (Ikenoue et al, 2003).…”

“…Early reports indicated that loss of heterozygosity (LOH) at the MCC locus is common, that is, B42% in colorectal cancers (Ashton-Rickardt et al, 1991), whereas somatic mutation of MCC is relatively rare, 3-7% (Nishisho et al, 1991). More recent studies have shown that the wild-type MCC protein may have a functional role in important cellular processes relevant in carcinogenesis, such as cell cycle regulation and the nuclear factor-kB (NF-kB) pathway (Matsumine et al, 1996;Bouwmeester et al, 2004). The activation and translocation of NF-kB to the nucleus is part of a signal-transduction pathway, which forms a basis for several physiologic and pathologic processes including cancer.…”