Open AccessWnt5a Signals through DVL1 to Repress Ribosomal DNA Transcription by RNA Polymerase I
Author(s) -
Randall A. Dass,
Aishe A. Sarshad,
Brittany B. Carson,
Jennifer M. Feenstra,
Amanpreet Kaur,
Aleš Obrdlík,
Matthew Parks,
Varsha Prakash,
Damon Love,
Kristian Pietras,
Rosa Serra,
Scott C. Blanchard,
Piergiorgio Percipalle,
Anthony M. Brown,
C. Theresa Vincent
Publication year - 2016
Publication title -
plos genetics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.587
H-Index - 233
eISSN - 1553-7404
pISSN - 1553-7390
DOI - 10.1371/journal.pgen.1006217
Subject(s) - biology , ribosome biogenesis , rna polymerase i , transcription (linguistics) , wnt signaling pathway , rna polymerase ii , microbiology and biotechnology , promoter , genetics , signal transduction , gene , gene expression , rna , rna polymerase , ribosome , linguistics , philosophy
Ribosome biogenesis is essential for cell growth and proliferation and is commonly elevated in cancer. Accordingly, numerous oncogene and tumor suppressor signaling pathways target rRNA synthesis. In breast cancer, non-canonical Wnt signaling by Wnt5a has been reported to antagonize tumor growth. Here, we show that Wnt5a rapidly represses rDNA gene transcription in breast cancer cells and generates a chromatin state with reduced transcription of rDNA by RNA polymerase I (Pol I). These effects were specifically dependent on Dishevelled1 (DVL1), which accumulates in nucleolar organizer regions (NORs) and binds to rDNA regions of the chromosome. Upon DVL1 binding, the Pol I transcription activator and deacetylase Sirtuin 7 (SIRT7) releases from rDNA loci, concomitant with disassembly of Pol I transcription machinery at the rDNA promoter. These findings reveal that Wnt5a signals through DVL1 to suppress rRNA transcription. This provides a novel mechanism for how Wnt5a exerts tumor suppressive effects and why disruption of Wnt5a signaling enhances mammary tumor growth in vivo .