The lin-4 regulatory RNA controls developmental timing in Caenorhabditis elegans by blocking LIN-14 protein synthesis after the initiation of translation

Dev Biol. 1999 Dec 15;216(2):671-80. doi: 10.1006/dbio.1999.9523.


lin-4 encodes a small RNA that is complementary to sequences in the 3' untranslated region (UTR) of lin-14 mRNA and that acts to developmentally repress the accumulation of LIN-14 protein. This repression is essential for the proper timing of numerous events of Caenorhabditis elegans larval development. We have investigated the mechanism of lin-4 RNA action by examining the fate of lin-14 mRNA in vivo during the time that lin-4 RNA is expressed. Our results indicate that the rate of synthesis of lin-14 mRNA, its state of polyadenylation, its abundance in the cytoplasmic fraction, and its polysomal sedimentation profile do not change in response to the accumulation of lin-4 RNA. Our results indicate that association of lin-4 RNA with the 3' UTR of lin-14 mRNA permits normal biogenesis of lin-14 mRNA, and normal translational initiation, but inhibits step(s) thereafter, such as translational elongation and/or the release of stable LIN-14 protein.

MeSH terms

  • 3' Untranslated Regions / genetics
  • Animals
  • Caenorhabditis elegans / embryology*
  • Caenorhabditis elegans Proteins*
  • Centrifugation, Density Gradient
  • Down-Regulation / genetics
  • Helminth Proteins / antagonists & inhibitors*
  • Helminth Proteins / biosynthesis
  • Helminth Proteins / genetics
  • Nuclear Proteins*
  • Nucleic Acid Hybridization
  • Poly A / genetics
  • Polyribosomes / metabolism
  • Protein Biosynthesis*
  • RNA / metabolism*
  • RNA, Messenger / metabolism


  • 3' Untranslated Regions
  • Caenorhabditis elegans Proteins
  • Helminth Proteins
  • LIN-14 protein, C elegans
  • Nuclear Proteins
  • RNA, Messenger
  • Poly A
  • RNA