In vitro disassembly of the nuclear lamina and M phase-specific phosphorylation of lamins by cdc2 kinase

Cell. 1990 May 18;61(4):591-602. doi: 10.1016/0092-8674(90)90471-p.


The nuclear lamina is an intermediate filament-type network underlying the inner nuclear membrane. Phosphorylation of lamin proteins is believed to cause lamina disassembly during meiotic and mitotic M phase, but the M phase-specific lamin kinase has not been identified. Here we show that the cdc2 kinase, a major element implicated in controlling the eukaryotic cell cycle, phosphorylates chicken B-type lamins in vitro on sites that are specifically phosphorylated during M phase in vivo. Concomitantly, cdc2 kinase is capable of inducing lamina depolymerization upon incubation with isolated nuclei. One of the target sites of cdc2 kinase is identified as a motif (SPTR) conserved in the N-terminal domain of all lamin proteins. These results lead us to propose that mitotic disassembly of the nuclear lamina results from direct phosphorylation of lamins by cdc2 kinase.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Animals
  • CDC2 Protein Kinase
  • Cell Nucleus / metabolism
  • Chickens
  • In Vitro Techniques
  • Interphase / physiology
  • Lamins
  • Macromolecular Substances
  • Mitosis / physiology*
  • Molecular Sequence Data
  • Nuclear Envelope / metabolism*
  • Nuclear Proteins / genetics
  • Nuclear Proteins / metabolism*
  • Phosphoproteins / physiology*
  • Phosphorylation
  • Protein Kinase C / physiology
  • Protein Kinases / physiology*


  • Lamins
  • Macromolecular Substances
  • Nuclear Proteins
  • Phosphoproteins
  • Protein Kinases
  • Protein Kinase C
  • CDC2 Protein Kinase