The inner nuclear membrane protein p58 associates in vivo with a p58 kinase and the nuclear lamins

EMBO J. 1992 Nov;11(11):4027-36.

Abstract

p58, also referred to as the lamin B receptor, is an intrinsic protein of the inner nuclear membrane that binds in vitro to lamin B. Previous studies have demonstrated that p58 is phosphorylated in vivo and removal of its phosphate moieties affects lamin B binding. Using affinity-purified antipeptide antibodies, we have now immunoisolated p58 from bird erythrocyte lysates under isotonic, non-denaturing conditions. Analysis of the immunopurified material shows that five distinct proteins are tightly and specifically associated with p58. Two of these polypeptides can be identified as nuclear lamins A and B. The immunoisolate also contains a kinase activity that phosphorylates p58 in vivo and in vitro, exclusively at serine residues, as indicated by phosphoamino acid analysis and two-dimensional phosphopeptide mapping. Cell fractionation experiments and in vitro phosphorylation assays demonstrate that the p58 kinase resides in the nuclear envelope and is distinct from protein kinase A and cdc2 kinase, for both of which p58 is an in vitro substrate. These data suggest that p58 is interacting in vivo with a p58 kinase and the nuclear lamins.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Antibodies / isolation & purification
  • CDC2 Protein Kinase / metabolism
  • Cattle
  • Cell Membrane / metabolism
  • Cell Nucleus / metabolism*
  • Chromatography, Affinity
  • Erythrocytes / metabolism
  • HeLa Cells
  • Humans
  • Immunoblotting
  • Lamin Type B
  • Lamins
  • Molecular Sequence Data
  • Myocardium / enzymology
  • Nuclear Envelope / metabolism*
  • Nuclear Proteins / analysis
  • Nuclear Proteins / isolation & purification
  • Nuclear Proteins / metabolism*
  • Peptide Mapping
  • Phosphopeptides / isolation & purification
  • Phosphorylation
  • Protein Kinases / metabolism
  • Receptors, Cell Surface / analysis
  • Receptors, Cell Surface / isolation & purification
  • Receptors, Cell Surface / metabolism*
  • Receptors, Cytoplasmic and Nuclear*
  • Turkeys

Substances

  • Antibodies
  • Lamin Type B
  • Lamins
  • Nuclear Proteins
  • Phosphopeptides
  • Receptors, Cell Surface
  • Receptors, Cytoplasmic and Nuclear
  • lamin B receptor
  • Protein Kinases
  • CDC2 Protein Kinase