PAP-1, a novel target protein of phosphorylation by pim-1 kinase

Eur J Biochem. 2000 Aug;267(16):5168-78. doi: 10.1046/j.1432-1327.2000.01585.x.


Protooncogene, pim-1, has been reported to be a predisposition for lymphomagenesis along with myc, and its protein product, Pim-1, has been shown to be a serine/threonine protein kinase, whose activity is involved in proliferation and differentiation of blood cells. The signal transduction pathways neither to nor from Pim-1, however, have been clarified. We have cloned a cDNA encoding a novel Pim-1 binding protein, PAP-1, comprising 213 amino acids with a basic amino-acid cluster near the C-terminus. PAP-1 was colocalized with Pim-1 in human HeLa cell nuclei. The in vitro binding assays using GST fusion proteins of the wild-type and various deletion mutants revealed that the whole molecule of Pim-1 is required for the binding activity to PAP-1 and that Pim-1 binds to the region from amino-acid numbers 1-147 of PAP-1, or to two segments in the region. The association of PAP-1 with Pim-1 was also shown in vivo in transfected cells. Furthermore, PAP-1 was phosphorylated in vitro by Pim-1, but not a kinase-negative Pim-1 mutant. The two serine residues of PAP-1 at amino acids 204 and 206 near the C-terminus were phosphorylated by Pim-1. PAP-1 is thus thought to be a target protein for Pim-1 kinase.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Annexin A5 / metabolism*
  • Base Sequence
  • Binding Sites
  • COS Cells
  • Cloning, Molecular
  • Humans
  • Jurkat Cells
  • Kinetics
  • Molecular Sequence Data
  • Pancreatitis-Associated Proteins
  • Phosphorylation
  • Protein-Serine-Threonine Kinases / metabolism
  • Proto-Oncogene Proteins / chemistry
  • Proto-Oncogene Proteins / genetics
  • Proto-Oncogene Proteins / metabolism*
  • Proto-Oncogene Proteins c-pim-1
  • Recombinant Proteins / chemistry
  • Recombinant Proteins / metabolism
  • Sequence Alignment
  • Sequence Homology, Amino Acid
  • Substrate Specificity
  • U937 Cells


  • Annexin A5
  • Pancreatitis-Associated Proteins
  • Proto-Oncogene Proteins
  • REG3A protein, human
  • Recombinant Proteins
  • PIM1 protein, human
  • Protein-Serine-Threonine Kinases
  • Proto-Oncogene Proteins c-pim-1

Associated data

  • GENBANK/D78255