Isolation of new polar granule components in Drosophila reveals P body and ER associated proteins.
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.
Thomson
Travis
T
Department of Biology and Developmental Biology Research Initiative, McGill University, 1205 Avenue Docteur Penfield, Montreal, Que., Canada H3A 1B1.
Liu
Niankun
N
Arkov
Alexey
A
Lehmann
Ruth
R
Lasko
Paul
P
D000818:Animals; D003594:Cytoplasmic Granules / Q000378:metabolism* / Q000648:ultrastructure; D053487:DEAD-box RNA Helicases / Q000378:metabolism; D029721:Drosophila Proteins / Q000302:isolation & purification* / Q000378:metabolism*; D004331:Drosophila melanogaster / Q000196:embryology* / Q000235:genetics / Q000378:metabolism* / Q000648:ultrastructure; D004625:Embryo, Nonmammalian / Q000378:metabolism / Q000648:ultrastructure; D004721:Endoplasmic Reticulum / Q000378:metabolism* / Q000648:ultrastructure; D017344:Genes, Insect; D026901:Membrane Transport Proteins / Q000378:metabolism; D046912:Multiprotein Complexes / Q000378:metabolism; D009154:Mutation / Q000235:genetics
D029721:Drosophila Proteins; D026901:Membrane Transport Proteins; D046912:Multiprotein Complexes; C071597:tud protein, Drosophila; C088269:vas protein, Drosophila; D053487:DEAD-box RNA Helicases