title: Physical and functional interaction between the ID1 and p65 for activation of NF-κB.
abstract: Inhibitor of differentiation or DNA binding-1 (ID1) is an important helix-loop-helix (HLH) transcription factor involved in diverse biological functions including cell differentiation, proliferation, apoptosis, and senescence. Recently, it was reported that ID1 can activate the NF-κB signaling pathway in a variety of cancer cells and a T cell line, but the mechanisms involved in ID1-mediated transactivation of NF-κB are not clear. In this study, we demonstrate by both in vitro pull-down assays and a cell-based in vivo two-hybrid system that ID1-mediated NF-κB activation is due to its physical interaction with p65. We have identified that the transcriptional activation domain (TAD) in p65 and the HLH domain in ID1 are vital for their interaction. Interestingly, a single site mutation (Leu76) in the HLH domain of ID1 protein drastically decreased its ability to bind with p65. Using a dual-luciferase assay, we demonstrated that the interaction between ID1 and p65 modulates activation of the NF-κB signaling pathway in vivo. In addition, we demonstrated that, by affecting the nuclear translocation of p65, ID1 is essential in regulating TNF-α-induced p65 recruitment to its downstream target, the cellular inhibitor of apoptosis protein 2 (cIAP2) promoter.
authors.affiliation: College of Life Sciences, Shenzhen University, Shenzhen, China.
authors.forename: Xiao
authors.initials: X
authors.lastname: Peng
authors.forename: Yuna
authors.initials: Y
authors.lastname: Wang
authors.forename: Swapna
authors.initials: S
authors.lastname: Kolli
authors.forename: Junpeng
authors.initials: J
authors.lastname: Deng
authors.forename: Li
authors.initials: L
authors.lastname: Li
authors.forename: Zhixin
authors.initials: Z
authors.lastname: Wang
authors.forename: J Usha
authors.initials: JU
authors.lastname: Raj
authors.forename: Deming
authors.initials: D
authors.lastname: Gou
mesh_terms: D000595:Amino Acid Sequence; D017209:Apoptosis / Q000502:physiology; D000075747:Baculoviral IAP Repeat-Containing 3 Protein; D045744:Cell Line, Tumor; D005786:Gene Expression Regulation / Q000502:physiology; D006801:Humans; D051034:Inhibitor of Apoptosis Proteins / Q000378:metabolism; D051798:Inhibitor of Differentiation Protein 1 / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D008969:Molecular Sequence Data; D016328:NF-kappa B / Q000378:metabolism*; D011401:Promoter Regions, Genetic; D054730:Protein Interaction Domains and Motifs / Q000502:physiology; D051996:Transcription Factor RelA / Q000737:chemistry / Q000378:metabolism*; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology; D044767:Ubiquitin-Protein Ligases
chemical_list: C497453:ID1 protein, human; D051034:Inhibitor of Apoptosis Proteins; D051798:Inhibitor of Differentiation Protein 1; D016328:NF-kappa B; D051996:Transcription Factor RelA; D014409:Tumor Necrosis Factor-alpha; C494832:BIRC3 protein, human; D000075747:Baculoviral IAP Repeat-Containing 3 Protein; D044767:Ubiquitin-Protein Ligases