The P granule component PGL-1 promotes the localization and silencing activity of the PUF protein FBF-2 in germline stem cells

Development. 2012 Oct;139(20):3732-40. doi: 10.1242/dev.083980.


In the C. elegans germline, maintenance of undifferentiated stem cells depends on the PUF family RNA-binding proteins FBF-1 and FBF-2. FBF-1 and FBF-2 are 89% identical and are required redundantly to silence the expression of mRNAs that promote meiosis. Here we show that, despite their extensive sequence similarity, FBF-1 and FBF-2 have different effects on target mRNAs. FBF-1 promotes the degradation and/or transport of meiotic mRNAs out of the stem cell region, whereas FBF-2 prevents translation. FBF-2 activity depends on the P granule component PGL-1. PGL-1 is required to localize FBF-2 to perinuclear P granules and for efficient binding of FBF-2 to its mRNA targets. We conclude that multiple regulatory mechanisms converge on meiotic RNAs to ensure silencing in germline stem cells. Our findings also support the view that P granules facilitate mRNA silencing by providing an environment in which translational repressors can encounter their mRNA targets immediately upon exit from the nucleus.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Binding Sites
  • Caenorhabditis elegans / genetics*
  • Caenorhabditis elegans / metabolism
  • Caenorhabditis elegans Proteins / genetics
  • Caenorhabditis elegans Proteins / metabolism*
  • Embryonic Stem Cells / metabolism*
  • Gene Expression Regulation, Developmental
  • Germ Cells / metabolism*
  • Meiosis / genetics
  • RNA Interference*
  • RNA, Messenger / genetics*
  • RNA, Messenger / metabolism
  • RNA, Small Interfering
  • RNA-Binding Proteins / genetics
  • RNA-Binding Proteins / metabolism*


  • Caenorhabditis elegans Proteins
  • PGL-1 protein, C elegans
  • RNA, Messenger
  • RNA, Small Interfering
  • RNA-Binding Proteins
  • fem-3-binding protein, C elegans