Isolation of new polar granule components in Drosophila reveals P body and ER associated proteins

Mech Dev. 2008 Sep-Oct;125(9-10):865-73. doi: 10.1016/j.mod.2008.06.005. Epub 2008 Jun 12.

Abstract

Germ plasm, a specialized cytoplasm present at the posterior of the early Drosophila embryo, is necessary and sufficient for germ cell formation. Germ plasm is rich in mitochondria and contains electron dense structures called polar granules. To identify novel polar granule components we isolated proteins that associate in early embryos with Vasa (VAS) and Tudor (TUD), two known polar granule associated molecules. We identified Maternal expression at 31B (ME31B), eIF4A, Aubergine (AUB) and Transitional Endoplasmic Reticulum 94 (TER94) as components of both VAS and TUD complexes and confirmed their localization to polar granules by immuno-electron microscopy. ME31B, eIF4A and AUB are also present in processing (P) bodies, suggesting that polar granules, which are necessary for germ line formation, might be related to P bodies. Our recovery of ER associated proteins TER94 and ME31B confirms that polar granules are closely linked to the translational machinery and to mRNP assembly.

Publication types

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

MeSH terms

  • Animals
  • Cytoplasmic Granules / metabolism*
  • Cytoplasmic Granules / ultrastructure
  • DEAD-box RNA Helicases / metabolism
  • Drosophila Proteins / isolation & purification*
  • Drosophila Proteins / metabolism*
  • Drosophila melanogaster / embryology*
  • Drosophila melanogaster / genetics
  • Drosophila melanogaster / metabolism*
  • Drosophila melanogaster / ultrastructure
  • Embryo, Nonmammalian / metabolism
  • Embryo, Nonmammalian / ultrastructure
  • Endoplasmic Reticulum / metabolism*
  • Endoplasmic Reticulum / ultrastructure
  • Genes, Insect
  • Membrane Transport Proteins / metabolism
  • Multiprotein Complexes / metabolism
  • Mutation / genetics

Substances

  • Drosophila Proteins
  • Membrane Transport Proteins
  • Multiprotein Complexes
  • tud protein, Drosophila
  • vas protein, Drosophila
  • DEAD-box RNA Helicases