title: DSIF restricts NF-κB signaling by coordinating elongation with mRNA processing of negative feedback genes.
abstract: NF-κB is central for immune response and cell survival, and its deregulation is linked to chronic inflammation and cancer through poorly defined mechanisms. IκBα and A20 are NF-κB target genes and negative feedback regulators. Upon their activation by NF-κB, DSIF is recruited, P-TEFb is released, and their elongating polymerase II (Pol II) C-terminal domain (CTD) remains hypophosphorylated. We show that upon DSIF knockdown, mRNA levels of a subset of NF-κB targets are not diminished; yet much less IκBα and A20 protein are synthesized, and NF-κB activation is abnormally prolonged. Further analysis of IκBα and A20 mRNA revealed that a significant portion is uncapped, unspliced, and retained in the nucleus. Interestingly, the Spt5 C-terminal repeat (CTR) domain involved in elongation stimulation through P-TEFb is dispensable for IκBα and A20 regulation. These findings assign a function for DSIF in cotranscriptional mRNA processing when elongating Pol II is hypophosphorylated and define DSIF as part of the negative feedback regulation of NF-κB.
authors.affiliation: Department of Biological Chemistry, The Weizmann Institute of Science, Rehovot 76100, Israel.
authors.forename: Gil
authors.initials: G
authors.lastname: Diamant
authors.forename: Liat
authors.initials: L
authors.lastname: Amir-Zilberstein
authors.forename: Yuki
authors.initials: Y
authors.lastname: Yamaguchi
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Handa
authors.forename: Rivka
authors.initials: R
authors.lastname: Dikstein
mesh_terms: D004257:DNA Polymerase II / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism; D015536:Down-Regulation; D057809:HEK293 Cells; D006367:HeLa Cells; D006801:Humans; D020672:I-kappa B Proteins / Q000235:genetics / Q000378:metabolism; D047908:Intracellular Signaling Peptides and Proteins / Q000235:genetics / Q000378:metabolism; D019169:Jurkat Cells; D061986:MCF-7 Cells; D000072000:NF-KappaB Inhibitor alpha; D016328:NF-kappa B / Q000378:metabolism*; D009687:Nuclear Proteins / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D010766:Phosphorylation; D042925:Positive Transcriptional Elongation Factor B / Q000378:metabolism; D011401:Promoter Regions, Genetic; D017434:Protein Structure, Tertiary; D034622:RNA Interference; D012333:RNA, Messenger / Q000378:metabolism*; D034741:RNA, Small Interfering / Q000378:metabolism; D015398:Signal Transduction; D014157:Transcription Factors / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D035602:Transcriptional Elongation Factors; D000072598:Tumor Necrosis Factor alpha-Induced Protein 3
chemical_list: D004268:DNA-Binding Proteins; D020672:I-kappa B Proteins; D047908:Intracellular Signaling Peptides and Proteins; D016328:NF-kappa B; C000606204:NFKBIA protein, human; D009687:Nuclear Proteins; D012333:RNA, Messenger; D034741:RNA, Small Interfering; C112224:SUPT5H protein, human; D014157:Transcription Factors; D035602:Transcriptional Elongation Factors; D000072000:NF-KappaB Inhibitor alpha; D042925:Positive Transcriptional Elongation Factor B; D004257:DNA Polymerase II; C076529:TNFAIP3 protein, human; D000072598:Tumor Necrosis Factor alpha-Induced Protein 3