Phosphorylation of Tat-interactive protein 60 kDa by protein kinase C epsilon is important for its subcellular localisation

Int J Biochem Cell Biol. 2008;40(2):236-44. doi: 10.1016/j.biocel.2007.07.017. Epub 2007 Aug 6.

Abstract

Tat-interactive protein 60 kDa is a nuclear acetyltransferase that both coactivates and corepresses transcription factors and has a definitive function in the DNA damage response. Here, we provide evidence that Tat-interactive protein 60 kDa is phosphorylated by protein kinase C epsilon. In vitro, protein kinase C epsilon phosphorylates Tat-interactive protein 60 kDa on at least two sites within the acetyltransferase domain. In whole cells, activation of protein kinase C increases the levels of phosphorylated Tat-interactive protein 60 kDa and the interaction of Tat-interactive protein 60 kDa with protein kinase C epsilon. A phosphomimetic mutant Tat-interactive protein 60 kDa has distinct subcellular localisation compared to the wild-type protein in whole cells. Taken together, these findings suggest that the protein kinase C epsilon phosphorylation sites on Tat-interactive protein 60 kDa are important for its subcellular localisation. Regulation of the subcellular localisation of Tat-interactive protein 60 kDa via phosphorylation provides a novel means of controlling Tat-interactive protein 60 kDa function.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Catalytic Domain
  • Cells, Cultured
  • Histone Acetyltransferases / genetics
  • Histone Acetyltransferases / metabolism*
  • Humans
  • Isoenzymes / metabolism
  • Lysine Acetyltransferase 5
  • Mutagenesis, Site-Directed
  • Phosphorylation
  • Protein Binding
  • Protein Kinase C-epsilon / metabolism*
  • Protein Transport
  • Tissue Distribution

Substances

  • Isoenzymes
  • Histone Acetyltransferases
  • KAT5 protein, human
  • Lysine Acetyltransferase 5
  • Protein Kinase C-epsilon