PIAS3 suppresses NF-kappaB-mediated transcription by interacting with the p65/RelA subunit.
Nuclear factor-kappaB (NF-kappaB) is a transcription factor critical for key cellular processes, including immune response, apoptosis, and cell cycle progression. A yeast two-hybrid screening, using the Rel homology domain (RHD) of the p65 subunit (RelA) of NF-kappaB as bait, led to the isolation of PIAS3, previously identified as a specific inhibitor of STAT3. We show that PIAS3 can directly associate with p65 using an in vitro pull-down and in vivo coimmunoprecipitation assays. When overexpressed, PIAS3 inhibits NF-kappaB-dependent transcription induced by treatment with tumor necrosis factor alpha (TNF-alpha) or interleukin-1beta or by overexpression of TNF family receptors such as RANK, TNFR1, and CD30 or signal transducers of TNF receptor-associated factors (TRAFs), including TRAF2, TRAF5, and TRAF6. Downregulation of PIAS3 by RNA interference reverses its effect on TNF-alpha-mediated NF-kappaB activation. We found that an N-terminal region of PIAS3 is necessary for both the interaction with p65 and the transcriptional suppression activity. In addition, we found that an LXXLL coregulator signature motif located within the N-terminal region of PIAS3 is the minimal requirement for the interaction with p65. Furthermore, we demonstrate that PIAS3 interferes with p65 binding to the CBP coactivator, thereby resulting in a decreased NF-kappaB-dependent transcription. Taken together, these data suggest that PIAS3 may function in vivo as a modulator in suppressing the transcriptional activity of p65.
Jang
Hyun Duk
HD
Division of Molecular Life Sciences and Center for Cell Signaling Research, Ewha Womans University, Seoul 120-750, Korea.
Yoon
Kwiyeom
K
Shin
Young Joo
YJ
Kim
Jaesang
J
Lee
Soo Young
SY
D020816:Amino Acid Motifs; D000818:Animals; D015703:Antigens, CD / Q000378:metabolism; D015153:Blotting, Western; D002352:Carrier Proteins / Q000378:metabolism*; D002453:Cell Cycle; D002460:Cell Line; D004305:Dose-Response Relationship, Drug; D004789:Enzyme Activation; D005982:Glutathione Transferase / Q000378:metabolism; D006023:Glycoproteins / Q000378:metabolism; D006801:Humans; D007375:Interleukin-1 / Q000378:metabolism; D017730:Ki-1 Antigen / Q000378:metabolism; D008156:Luciferases / Q000378:metabolism; D016328:NF-kappa B / Q000378:metabolism* / Q000502:physiology*; D053244:Osteoprotegerin; D010957:Plasmids / Q000378:metabolism; D011233:Precipitin Tests; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D011506:Proteins / Q000378:metabolism; D034622:RNA Interference; D034741:RNA, Small Interfering / Q000378:metabolism; D018160:Receptors, Cytoplasmic and Nuclear / Q000378:metabolism; D018124:Receptors, Tumor Necrosis Factor / Q000378:metabolism; D047888:Receptors, Tumor Necrosis Factor, Type I; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D015398:Signal Transduction; D048015:TNF Receptor-Associated Factor 5; D048029:TNF Receptor-Associated Factor 6; D013997:Time Factors; D051996:Transcription Factor RelA; D014158:Transcription, Genetic; D014162:Transfection; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism; D020798:Two-Hybrid System Techniques
D015703:Antigens, CD; D002352:Carrier Proteins; D006023:Glycoproteins; D007375:Interleukin-1; D017730:Ki-1 Antigen; D016328:NF-kappa B; D053244:Osteoprotegerin; D011506:Proteins; D034741:RNA, Small Interfering; D018160:Receptors, Cytoplasmic and Nuclear; D018124:Receptors, Tumor Necrosis Factor; D047888:Receptors, Tumor Necrosis Factor, Type I; D011993:Recombinant Fusion Proteins; D048015:TNF Receptor-Associated Factor 5; D048029:TNF Receptor-Associated Factor 6; C506030:TNFRSF11B protein, human; D051996:Transcription Factor RelA; D014409:Tumor Necrosis Factor-alpha; D008156:Luciferases; D005982:Glutathione Transferase