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Citation
Grewal, S.S., Evans, J.R., Edgar, B.A. (2007). Drosophila TIF-IA is required for ribosome synthesis and cell growth and is regulated by the TOR pathway.  J. Cell Biol. 179(6): 1105--1113.
FlyBase ID
FBrf0201642
Publication Type
Research paper
Abstract

Synthesis of ribosomal RNA (rRNA) is a key step in ribosome biogenesis and is essential for cell growth. Few studies, however, have investigated rRNA synthesis regulation in vivo in multicellular organisms. Here, we present a genetic analysis of transcription initiation factor IA (TIF-IA), a conserved RNA polymerase I transcription factor. Drosophila melanogaster Tif-IA(-/-) mutants have reduced levels of rRNA synthesis and sustain a developmental arrest caused by a block in cellular growth. We find that the target of rapamycin (TOR) pathway regulates TIF-IA recruitment to rDNA. Furthermore, we show that the TOR pathway regulates rRNA synthesis in vivo and that TIF-IA overexpression can maintain rRNA transcription when TOR activity is reduced in developing larvae. We propose that TIF-IA acts in vivo as a downstream growth-regulatory target of the TOR pathway. Overexpression of TIF-IA also elevates levels of both 5S RNA and messenger RNAs encoding ribosomal proteins. Stimulation of rRNA synthesis by TIF-IA may therefore provide a feed-forward mechanism to coregulate the levels of other ribosome components.

PubMed ID
PubMed Central ID
PMC2140016 (PMC) (EuropePMC)
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Secondary IDs
    Language of Publication
    English
    Additional Languages of Abstract
    Parent Publication
    Publication Type
    Journal
    Abbreviation
    J. Cell Biol.
    Title
    Journal of Cell Biology
    Publication Year
    1966-
    ISBN/ISSN
    0021-9525
    Data From Reference
    Alleles (9)
    Genes (19)
    Cell Lines (1)
    Natural transposons (1)
    Insertions (2)
    Experimental Tools (2)
    Transgenic Constructs (6)