The DEXD/H-box RNA helicase RHII/Gu is a co-factor for c-Jun-activated transcription.
Tandem affinity purification (TAP) and mass spectrometric peptide sequencing showed that the DEAD-box RNA helicase RHII/Gu is a functional interaction partner of c-Jun in human cells. The N-terminal transcription activation region of, c-Jun interacts with a C-terminal domain of RHII/Gu. This interaction is stimulated by anisomycin treatment in a manner that is concurrent with, but independent of, c-Jun phosphorylation. A possible explanation for this effect is provided by the observation that RHII/Gu translocates from nucleolus to nucleoplasm upon anisomycin or UV treatment or when JNK signaling is activated by overexpression of a constitutively active form of MEKK1 kinase. Several experiments show that the RNA helicase activity of RHII/Gu supports c-Jun-mediated target gene activation: dominant-negative forms of RHII/Gu, as well as a neutralizing antibody against the enzyme, significantly interfered with c-Jun target gene activity but not with transcription in general. These findings clarify the mechanism of c-Jun-mediated transcriptional regulation, and provide evidence for an involvement of RHII/Gu in stress response and in RNA polymerase II-catalyzed transcription in mammalian cells.
Westermarck
Jukka
J
EMBL, D-69117 Heidelberg, Germany.
Weiss
Carsten
C
Saffrich
Rainer
R
Kast
Jürgen
J
Musti
Anna-Maria
AM
Wessely
Matthias
M
Ansorge
Wilhelm
W
Séraphin
Bertrand
B
Wilm
Matthias
M
Valdez
Benigno C
BC
Bohmann
Dirk
D
D000818:Animals; D002454:Cell Differentiation / Q000235:genetics; D053487:DEAD-box RNA Helicases; D006801:Humans; D016716:PC12 Cells; D011485:Protein Binding; D016755:Proto-Oncogene Proteins c-jun / Q000235:genetics* / Q000378:metabolism; D020365:RNA Helicases / Q000235:genetics* / Q000378:metabolism; D051381:Rats; D014158:Transcription, Genetic; D015533:Transcriptional Activation
D016755:Proto-Oncogene Proteins c-jun; C448980:DDX50 protein, human; D053487:DEAD-box RNA Helicases; D020365:RNA Helicases