Dynamics of PLC? and Src family kinase 1 interactions during nuclear envelope formation revealed by FRET-FLIM.

ABSTRACT: The nuclear envelope (NE) breaks down and reforms during each mitotic cycle. A similar process happens to the sperm NE following fertilisation. The formation of the NE in both these circumstances involves endoplasmic reticulum membranes enveloping the chromatin, but PLC?-dependent membrane fusion events are also essential. Here we demonstrate the activation of PLC? by a Src family kinase (SFK1) during NE assembly. We show by time-resolved FRET for the first time the direct in vivo interaction and temporal regulation of PLC? and SFK1 in sea urchins. As a prerequisite for protein activation, there is a rapid phosphorylation of PLC? on its Y783 residue in response to GTP in vitro. This phosphorylation is dependent upon SFK activity; thus Y783 phosphorylation and NE assembly are susceptible to SFK inhibition. Y783 phosphorylation is also observed on the surface of the male pronucleus (MPN) in vivo during NE formation. Together the corroborative in vivo and in vitro data demonstrate the phosphorylation and activation of PLC? by SFK1 during NE assembly. We discuss the potential generality of such a mechanism.

SUBMITTER: Byrne RD 

PROVIDER: S-EPMC3404105 | biostudies-literature | 2012

REPOSITORIES: biostudies-literature