PWP1 Mediates Nutrient-Dependent Growth Control through Nucleolar Regulation of Ribosomal Gene Expression

: Ying Liu, Jaakko Mattila, Sami Ventelä, Leena Yadav, Wei Zhang, Nicole Lamichane, Jari Sundström, Otto Kauko, Reidar Grénman, Markku Varjosalo, Jukka Westermarck, Ville Hietakangas

Publisher: CELL PRESS

: 2017

: Developmental Cell

: DEVELOPMENTAL CELL

: DEV CELL

: 43

: 2

: 240

: 252

: 18

: 1534-5807

: 1878-1551

DOI: https://doi.org/10.1016/j.devcel.2017.09.022

Ribosome biogenesis regulates animal growth and is controlled by nutrient-responsive mTOR signaling. How ribosome biogenesis is regulated during the developmental growth of animals and how nutrient-responsive signaling adjusts ribosome biogenesis in this setting have remained insufficiently understood. We uncover PWP1 as a chromatin-associated regulator of developmental growth with a conserved role in RNA polymerase I (Pol I)-mediated rRNA transcription. We further observed that PWP1 epigenetically maintains the rDNA loci in a transcription-competent state. PWP1 responds to nutrition in Drosophila larvae via mTOR signaling through gene expression and phosphorylation, which controls the nucleolar localization of dPWP1. Our data further imply that dPWP1 acts synergistically with mTOR signaling to regulate the nucleolar localization of TFIIH, a known elongation factor of Pol I. Ribosome biogenesis is often deregulated in cancer, and we demonstrate that high PWP1 levels in human head and neck squamous cell carcinoma tumors are associated with poor prognosis.