A Secreted RNA Binding Protein Forms RNA-Stabilizing Granules in the Honeybee Royal Jelly

Mol Cell. 2019 May 2;74(3):598-608.e6. doi: 10.1016/j.molcel.2019.03.010. Epub 2019 Apr 18.


RNA flow between organisms has been documented within and among different kingdoms of life. Recently, we demonstrated horizontal RNA transfer between honeybees involving secretion and ingestion of worker and royal jellies. However, how the jelly facilitates transfer of RNA is still unknown. Here, we show that worker and royal jellies harbor robust RNA-binding activity. We report that a highly abundant jelly component, major royal jelly protein 3 (MRJP-3), acts as an extracellular non-sequence-specific RNA-aggregating factor. Multivalent RNA binding stimulates higher-order assembly of MRJP-3 into extracellular ribonucleoprotein granules that protect RNA from degradation and enhance RNA bioavailability. These findings reveal that honeybees have evolved a secreted dietary RNA-binding factor to concentrate, stabilize, and share RNA among individuals. Our work identifies high-order ribonucleoprotein assemblies with functions outside cells and organisms.

Keywords: RNA binding protein; RNA transmission; RNP; RNP granules; environmental RNA; extracellular RNPs; honey bees; phase transition; royal jelly; transmissible RNA.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Bees / genetics*
  • Fatty Acids / biosynthesis
  • Fatty Acids / genetics*
  • Gene Transfer, Horizontal / genetics*
  • Glycoproteins / genetics*
  • Insect Proteins / genetics*
  • Phase Transition
  • RNA / genetics
  • RNA Transport / genetics
  • RNA-Binding Proteins / genetics


  • Fatty Acids
  • Glycoproteins
  • Insect Proteins
  • MRJP3 protein, Apis mellifera
  • RNA-Binding Proteins
  • RNA
  • royal jelly