PUBLICATION
Sequential PKC- and Cdc2-mediated phosphorylation events elicit zebrafish nuclear envelope disassembly
- Authors
- Collas, P.
- ID
- ZDB-PUB-990420-3
- Date
- 1999
- Source
- Journal of Cell Science 112: 977-987 (Journal)
- Registered Authors
- Collas, Philippe
- Keywords
- nuclear envelope; phosphorylation; PKC; Cdc2 kinase; Danio rerio
- MeSH Terms
-
- Animals
- CDC2 Protein Kinase/metabolism*
- Female
- Humans
- Meiosis
- Membrane Proteins/metabolism
- Metaphase
- Nuclear Envelope/physiology*
- Nuclear Envelope/ultrastructure
- Nuclear Proteins/metabolism
- Oocytes/physiology
- Oocytes/ultrastructure
- Phosphoproteins/metabolism
- Phosphorylation
- Protein Kinase C/metabolism*
- Zebrafish
- PubMed
- 10036247 Full text @ J. Cell Sci.
Citation
Collas, P. (1999) Sequential PKC- and Cdc2-mediated phosphorylation events elicit zebrafish nuclear envelope disassembly. Journal of Cell Science. 112:977-987.
Abstract
Molecular markers of the zebrafish inner nuclear membrane (NEP55) and nuclear lamina (L68) were identified, partially characterized and used to demonstrate that disassembly of the zebrafish nuclear envelope requires sequential phosphorylation events by first PKC, then Cdc2 kinase. NEP55 and L68 are immunologically and functionally related to human LAP2beta and lamin B, respectively. Exposure of zebrafish nuclei to meiotic cytosol elicits rapid phosphorylation of NEP55 and L68, and disassembly of both proteins. L68 phosphorylation is completely inhibited by simultaneous inhibition of Cdc2 and PKC and only partially blocked by inhibition of either kinase. NEP55 phosphorylation is completely prevented by inhibition or immunodepletion of cytosolic Cdc2. Inhibition of cAMP-dependent kinase, MEK or CaM kinase II does not affect NEP55 or L68 phosphorylation. In vitro, nuclear envelope disassembly requires phosphorylation of NEP55 and L68 by both mammalian PKC and Cdc2. Inhibition of either kinase is sufficient to abolish NE disassembly. Furthermore, novel two-step phosphorylation assays in cytosol and in vitro indicate that PKC-mediated phosphorylation of L68 prior to Cdc2-mediated phosphorylation of L68 and NEP55 is essential to elicit nuclear envelope breakdown. Phosphorylation elicited by Cdc2 prior to PKC prevents nuclear envelope disassembly even though NEP55 is phosphorylated. The results indicate that sequential phosphorylation events elicited by PKC, followed by Cdc2, are required for zebrafish nuclear disassembly. They also argue that phosphorylation of inner nuclear membrane integral proteins is not sufficient to promote nuclear envelope breakdown, and suggest a multiple-level regulation of disassembly of nuclear envelope components during meiosis and at mitosis.
Genes / Markers
Expression
Phenotype
Mutations / Transgenics
Human Disease / Model
Sequence Targeting Reagents
Fish
Orthology
Engineered Foreign Genes
Mapping