Bicaudal-C associates with a Trailer Hitch/Me31B complex and is required for efficient Gurken secretion

Dev Biol. 2009 Apr 1;328(1):160-72. doi: 10.1016/j.ydbio.2009.01.024. Epub 2009 Feb 10.


Bicaudal-C (Bic-C) is a multiple KH-domain RNA-binding protein required for Drosophila oogenesis and, maternally, for embryonic patterning. In early oogenesis, Bic-C negatively regulates target mRNAs, including Bic-C, by recruiting the CCR4 deadenylase through a direct association with its NOT3 subunit. Here, we identify a novel function for Bic-C in secretion of the TGF-alpha homolog Gurken (Grk). In Bic-C mutant egg chambers, Grk is sequestered within actin-coated structures during mid-oogenesis. As a consequence, Egfr signalling is not efficiently activated in the dorsal-anterior follicle cells. This phenotype is strikingly similar to that of trailer hitch (tral) mutants. Consistent with the idea that Bic-C and Tral act together in Grk secretion, Bic-C co-localizes with Tral within cytoplasmic granules, and can be co-purified with multiple protein components of a Tral mRNP complex. Taken together, our results implicate translational regulation by Bic-C and Tral in the secretory pathway.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • DEAD-box RNA Helicases / metabolism*
  • Drosophila / embryology
  • Drosophila / genetics
  • Drosophila / metabolism
  • Drosophila Proteins / genetics
  • Drosophila Proteins / metabolism*
  • Drosophila Proteins / physiology*
  • Embryo, Nonmammalian
  • Mutation
  • Oogenesis / genetics
  • RNA-Binding Proteins / genetics
  • RNA-Binding Proteins / metabolism
  • RNA-Binding Proteins / physiology*
  • Ribonucleoproteins / metabolism*
  • Transforming Growth Factor alpha / metabolism*


  • BicC protein, Drosophila
  • Drosophila Proteins
  • RNA-Binding Proteins
  • Ribonucleoproteins
  • TRAL protein, Drosophila
  • Transforming Growth Factor alpha
  • grk protein, Drosophila
  • Me31B protein, Drosophila
  • DEAD-box RNA Helicases