Vesicular PtdIns(3,4,5)P3 and Rab7 are key effectors of sea urchin zygote nuclear membrane fusion

Marta G Lete, Richard D Byrne, Alicia Alonso, Dominic Poccia, Banafshé Larijani

Research output: Contribution to journalArticle

2 Citations (Scopus)

Abstract

Regulation of nuclear envelope dynamics is an important example of the universal phenomena of membrane fusion. The signalling molecules involved in nuclear membrane fusion might also be conserved during the formation of both pronuclear and zygote nuclear envelopes in the fertilised egg. Here, we determine that class-I phosphoinositide 3-kinases (PI3Ks) are needed for in vitro nuclear envelope formation. We show that, in vivo, PtdIns(3,4,5)P3 is transiently located in vesicles around the male pronucleus at the time of nuclear envelope formation, and around male and female pronuclei before membrane fusion. We illustrate that class-I PI3K activity is also necessary for fusion of the female and male pronuclear membranes. We demonstrate, using coincidence amplified Förster resonance energy transfer (FRET) monitored using fluorescence lifetime imaging microscopy (FLIM), a protein-lipid interaction of Rab7 GTPase and PtdIns(3,4,5)P3 that occurs during pronuclear membrane fusion to create the zygote nuclear envelope. We present a working model, which includes several molecular steps in the pathways controlling fusion of nuclear envelope membranes.

Original languageEnglish
Pages (from-to)444-452
Number of pages9
JournalJournal of Cell Science
Volume130
Issue number2
DOIs
Publication statusPublished - 15 Jan 2017

Keywords

  • Animals
  • Female
  • Fertilization
  • Male
  • Membrane Fusion
  • Models, Biological
  • Nuclear Envelope/metabolism
  • Paracentrotus/metabolism
  • Phosphatidylinositol 3-Kinases/antagonists & inhibitors
  • Phosphatidylinositol Phosphates/metabolism
  • Transport Vesicles/metabolism
  • Zygote/metabolism
  • rab GTP-Binding Proteins/metabolism

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