M. Lete, R. Byrne, A. Alonso, D. Poccia, and B. Larijani
2017 Journal of Cell Science 130: 444-452
Regulation of nuclear envelope dynamics is an important example of the universal phenomenon of membrane fusion regulation. Here, we determine that Class I PI3-kinases are needed for in vitro nuclear envelope formation. 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 prior to membrane fusion. Class I PI3-kinase activity is also necessary for fusion of the female and male pronuclear membranes.
We demonstrate by coincidence amplified-FRET monitored by FLIM that protein-lipid interaction of Rab7 GTPase and PtdIns(3,4,5)P3 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 NE membranes.