Phosphorylation of High-Mobility-Group Protein 14 by Two Specific Kinases Modifies Its Interaction With Histone Oligomers in Free Solution

Biochim Biophys Acta. 1987 Aug 25;909(3):190-200. doi: 10.1016/0167-4781(87)90077-7.

Abstract

Chromosomal protein HMG14 can be specifically phosphorylated by the cyclic AMP-dependent protein kinase at the N-terminus and by casein kinase 2 at the acidic C-terminus. Under the same conditions used for HMG14, HMG17 is not significantly phosphorylated by either of the two kinases. Further, we have studied the effect of phosphorylation by these kinases on the interaction of HMG14 with histone oligomers, using chemical cross-linking. Our results indicate that the phosphorylation of HMG14 by casein kinase 2 enhances its interaction with histone oligomers in free solution, whereas a minor effect was observed by phosphorylation with cyclic AMP-dependent protein kinase. In contrast, HMG17 does not interact at all with any histone oligomer in free solution under the conditions used. To gain insight into the possible effect that phosphorylation may play in vivo, the pattern of distribution among different chromatin fractions was analysed. It was found that, although phosphorylation of HMG14 by both kinases allowed reconstitution of HMG14 to chromatin, the patterns obtained showed some slight differences.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Casein Kinases
  • Cattle
  • Chromatin / metabolism
  • Cross-Linking Reagents
  • Cyclic AMP / pharmacology*
  • High Mobility Group Proteins / metabolism*
  • Histones / metabolism*
  • Isoelectric Point
  • Macromolecular Substances
  • Peptide Fragments / isolation & purification
  • Phosphorylation
  • Protein Kinases / metabolism*
  • Rats
  • Solutions

Substances

  • Chromatin
  • Cross-Linking Reagents
  • High Mobility Group Proteins
  • Histones
  • Macromolecular Substances
  • Peptide Fragments
  • Solutions
  • Cyclic AMP
  • Protein Kinases
  • Casein Kinases