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

A1 Journal article (refereed)


Internal Authors/Editors


Publication Details

List of Authors: Tim H. Holmström, Antoine Mialon, Marko Kallio, Yvonne Nymalm, Leni Mannermaa, Tina Holm, Henrik Johansson, Elizabeth Black, David Gillespie, Tiina A. Salminen, Ülo Langel, Benigno C. Valdez., Jukka Westermarck
Publisher: AMER SOC BIOCHEMISTRY MOLECULAR BIOLOGY INC
Publication year: 2008
Journal: Journal of Biological Chemistry
Journal acronym: J BIOL CHEM
Volume number: 283
Start page: 7046
End page: 7053
Number of pages: 8
ISSN: 0021-9258


Abstract

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.

Last updated on 2019-22-09 at 04:21