title: AWP1 binds to tumor necrosis factor receptor-associated factor 2 (TRAF2) and is involved in TRAF2-mediated nuclear factor-kappaB signaling.
abstract: Tumor necrosis factor receptor-associated factor 2 (TRAF2) is an adaptor protein which involves in the activation of the transcription factor, nuclear factor kappaB (NF-κB), in the tumor necrosis factor (TNF) receptor pathway. This signaling is modulated by proteins that interact with tumor necrosis factor receptor-associated factor 2. In this study, we identified the zinc-finger protein AWP1 as a tumor necrosis factor receptor-associated factor 2-interacting protein through yeast two-hybrid screening. We found that AWP1 directly interacted with the C-terminal tumor necrosis factor receptor-associated factor (TRAF) domain of tumor necrosis factor receptor-associated factor 2. Knockdown of AWP1 using small hairpin RNA significantly decreased nuclear factor kappaB activity but increased tumor necrosis factor alpha (TNFα)-induced apoptosis, presumably by decreasing the induction of nuclear factor kappaB-responsive anti-apoptotic molecules, including FICE-like inhibitory protein (FLIP), X-linked inhibitor of apoptosis protein (XIAP), Bcl-2, and Bcl-xL. In contrast, overexpression of wild-type AWP1 inhibited nuclear factor kappaB activation. Detailed domain mapping experiments showed that the AN1 domain of AWP1 mediated the functional interaction with tumor necrosis factor receptor-associated factor 2, and the A20 domain was responsible for the negative regulation of nuclear factor kappaB activation. Importantly, ectopic AWP1 overexpression led to an A20 domain-dependent increase in K-48 ubiquitination of tumor necrosis factor receptor-associated factor 2. These data indicate that AWP1 binds to tumor necrosis factor receptor-associated factor 2 and that regulates tumor necrosis factor alpha-induced nuclear factor kappaB activation through two distinct domains.
authors.affiliation: Department of Medicine, Graduate School, University of Ulsan College of Medicine, Seoul 138-736, Republic of Korea. ejchang@amc.seoul.kr
authors.forename: Eun-Ju
authors.initials: EJ
authors.lastname: Chang
authors.forename: Jeongim
authors.initials: J
authors.lastname: Ha
authors.forename: Soon-Suk
authors.initials: SS
authors.lastname: Kang
authors.forename: Zang Hee
authors.initials: ZH
authors.lastname: Lee
authors.forename: Hong-Hee
authors.initials: HH
authors.lastname: Kim
mesh_terms: D048868:Adaptor Proteins, Signal Transducing / Q000037:antagonists & inhibitors / Q000737:chemistry / Q000235:genetics; D001665:Binding Sites; D020868:Gene Silencing; D057809:HEK293 Cells; D006367:HeLa Cells; D006801:Humans; D016328:NF-kappa B; D010957:Plasmids; D011485:Protein Binding; D025941:Protein Interaction Mapping; D017434:Protein Structure, Tertiary; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000235:genetics / Q000378:metabolism; D034741:RNA, Small Interfering; D047889:Receptors, Tumor Necrosis Factor, Type II / Q000235:genetics / Q000378:metabolism; D015398:Signal Transduction / Q000235:genetics*; D047990:TNF Receptor-Associated Factor 1 / Q000235:genetics / Q000378:metabolism; D047992:TNF Receptor-Associated Factor 2 / Q000235:genetics / Q000378:metabolism*; D014162:Transfection; D014409:Tumor Necrosis Factor-alpha / Q000235:genetics / Q000378:metabolism; D020798:Two-Hybrid System Techniques; D054875:Ubiquitination; D051636:X-Linked Inhibitor of Apoptosis Protein / Q000235:genetics / Q000378:metabolism
chemical_list: D048868:Adaptor Proteins, Signal Transducing; D016328:NF-kappa B; D019253:Proto-Oncogene Proteins c-bcl-2; D034741:RNA, Small Interfering; D047889:Receptors, Tumor Necrosis Factor, Type II; D047990:TNF Receptor-Associated Factor 1; D047992:TNF Receptor-Associated Factor 2; D014409:Tumor Necrosis Factor-alpha; D051636:X-Linked Inhibitor of Apoptosis Protein; C496866:XIAP protein, human; C417945:ZFAND6 protein, human