DSIF Restricts NF-κB Signaling by Coordinating Elongation with mRNA Processing of Negative Feedback Genes

Autor: Gil Diamant, Liat Amir-Zilberstein, Yuki Yamaguchi, Hiroshi Handa, Rivka Dikstein
Jazyk: angličtina
Rok vydání: 2012
Předmět:
Zdroj: Cell Reports, Vol 2, Iss 4, Pp 722-731 (2012)
Druh dokumentu: article
ISSN: 2211-1247
DOI: 10.1016/j.celrep.2012.08.041
Popis: 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.
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