Phosphorylation of human high mobility group N1 protein by protein kinase CK2

Biochem Biophys Res Commun. 2006 Jul 14;345(4):1497-503. doi: 10.1016/j.bbrc.2006.05.055. Epub 2006 May 16.

Abstract

High mobility group (HMG) N1 protein, formerly known as HMG 14, is a member of the chromosomal HMG protein family. Protein kinase CK2 was previously reported to be able to phosphorylate bovine HMGN1 in vitro; Ser89 and Ser99, corresponding to Ser88 and Ser98 in human HMGN1, were shown to be major and minor recognition sites, respectively. In this report, we employed mass spectrometry and examined both the extent and the sites of phosphorylation in HMGN1 protein catalyzed by recombinant human protein kinase CK2. We found that five serine residues, i.e., Ser6, Ser7, Ser85, Ser88, and Ser98, in HMGN1 can be phosphorylated by the kinase in vitro. All five sites were previously shown to be phosphorylated in MCF-7 human breast cancer cells in vivo. Among these five sites, Ser6, Ser7, and Ser85 were new sites of phosphorylation induced by protein kinase CK2 in vitro.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Binding Sites / genetics
  • Casein Kinase II / genetics
  • Casein Kinase II / metabolism*
  • Cell Line, Tumor
  • HMGN1 Protein / chemistry
  • HMGN1 Protein / genetics
  • HMGN1 Protein / metabolism*
  • Humans
  • Molecular Sequence Data
  • Phosphorylation
  • Recombinant Proteins / metabolism
  • Serine / chemistry
  • Serine / genetics
  • Serine / metabolism
  • Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization

Substances

  • HMGN1 Protein
  • Recombinant Proteins
  • Serine
  • Casein Kinase II