c-Jun supports ribosomal RNA processing and nucleolar localization of RNA helicase DDX21

A1 Originalartikel i en vetenskaplig tidskrift (referentgranskad)

Interna författare/redaktörer

Publikationens författare: Holmstrom TH, Mialon A, Kallio M, Nymalm Y, Mannermaa L, Holm T, Johansson H, Black E, Gillespie D, Salminen TA, Langel U, Valdez BC, Westermarck J
Publiceringsår: 2008
Tidskrift: Journal of Biological Chemistry
Tidskriftsakronym: J BIOL CHEM
Volym: 283
Artikelns första sida, sidnummer: 7046
Artikelns sista sida, sidnummer: 7053
Antal sidor: 8
ISSN: 0021-9258


The molecular mechanisms by which the AP-1 transcription factor c-Jun exerts its biological functions are not clearly understood. In addition to its well established role in transcriptional regulation of gene expression, several reports have suggested that c-Jun may also regulate cell behavior by non-transcriptional mechanisms. Here, we report that small interfering RNA-mediated depletion of c-Jun from mammalian cells results in inhibition of 28 S and 18 S rRNA accumulation. Moreover, we show that c-Jun depletion results in partial translocation of RNA helicase DDX21, implicated in rRNA processing, from the nucleolus to the nucleoplasm. We demonstrate that DDX21 translocation is rescued by exogenous c-Jun expression and that c-Jun depletion inhibits rRNA binding of DDX21. Furthermore, the direct interaction between c-Jun and DDX21 regulates nucleolar localization of DDX21. These results demonstrate that in addition to its transcriptional effects, c-Jun regulates rRNA processing and nucleolar compartmentalization of the rRNA processing protein DDX21. Thus, our results demonstrate a nucleolar mechanism through which c-Jun can regulate cell behavior. Moreover, these results suggest that the phenotypes observed previously in c-Jun-depleted mouse models and cell lines could be partly due to the effects of c-Jun on rRNA processing.

Senast uppdaterad 2019-19-06 vid 05:29