Role for phosphatidylinositol in nuclear envelope formation

B. Larijani, T. M. Barona, D. L. Poccia

Research output: Contribution to journalArticlepeer-review

Abstract

PtdIns is a minor membrane phospholipid that is important in signal transduction. Recently, derivatives of PtdIns phosphorylated at the 3-position of the inositol ring have been implicated in the regulation of constitutive membrane traffic and in membrane fusion events. Assembly of the nuclear envelope (NE), a crucial step in the progress of mitosis, is also likely to involve membrane fusion reactions. We therefore investigated the role of PtdIns and phosphoinositide 3-kinase (PI-3K) activity in NE formation in vitro. GTP-induced NE formation was blocked by wortmannin and LY294002, two specific inhibitors of PI-3K, suggesting a role for PtdIns phosphorylated at the 3-position. PtdIns-specific phospholipase C mimicked GTP hydrolysis as an inducer of NE formation. This induction was dependent on a membrane vesicle subfraction (MV1) that was highly enriched in PtdIns, as determined by heteronuclear two-dimensional NMR spectroscopy. On the basis of these results, we suggest that the MV1 population serves as a source of membranes rich in PtdIns that might facilitate fusion, possibly through the production of the membrane-destabilizing lipid diacylglycerol.

Original languageEnglish
Pages (from-to)495-501
Number of pages7
JournalBiochemical Journal
Volume356
Issue number2
DOIs
Publication statusPublished - 1 Jun 2001

Keywords

  • Membrane vesicle fusion
  • Phosphatidylinositol-specific phospholipase C
  • Phosphoinositide 3-kinase
  • Two-dimensional NMR

ASJC Scopus subject areas

  • Biochemistry
  • Molecular Biology
  • Cell Biology

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