Analysis of the subcellular localization of the human histone methyltransferase SETDB1

Biochem Biophys Res Commun. 2015 Oct 2;465(4):725-31. doi: 10.1016/j.bbrc.2015.08.065. Epub 2015 Aug 18.

Abstract

SET domain, bifurcated 1 (SETDB1) is a histone methyltransferase that methylates lysine 9 on histone H3. Although it is important to know the localization of proteins to elucidate their physiological function, little is known of the subcellular localization of human SETDB1. In the present study, to investigate the subcellular localization of hSETDB1, we established a human cell line constitutively expressing enhanced green fluorescent protein fused to hSETDB1. We then generated a monoclonal antibody against the hSETDB1 protein. Expression of both exogenous and endogenous hSETDB1 was observed mainly in the cytoplasm of various human cell lines. Combined treatment with the nuclear export inhibitor leptomycin B and the proteasome inhibitor MG132 led to the accumulation of hSETDB1 in the nucleus. These findings suggest that hSETDB1, localized in the nucleus, might undergo degradation by the proteasome and be exported to the cytosol, resulting in its detection mainly in the cytosol.

Keywords: Histone methyltransferase; Monoclonal antibody; Protein localization; SETDB1.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Active Transport, Cell Nucleus / drug effects
  • Amino Acid Sequence
  • Cell Line
  • Cell Nucleus / metabolism
  • Cytoplasm / metabolism
  • Fatty Acids, Unsaturated / pharmacology
  • Green Fluorescent Proteins / genetics
  • Green Fluorescent Proteins / metabolism
  • HEK293 Cells
  • HeLa Cells
  • Hep G2 Cells
  • Histone-Lysine N-Methyltransferase
  • Humans
  • Karyopherins / antagonists & inhibitors
  • Leupeptins / pharmacology
  • Molecular Sequence Data
  • Proteasome Endopeptidase Complex / metabolism
  • Proteasome Inhibitors / pharmacology
  • Protein Methyltransferases / genetics
  • Protein Methyltransferases / metabolism*
  • Receptors, Cytoplasmic and Nuclear / antagonists & inhibitors
  • Recombinant Fusion Proteins / genetics
  • Recombinant Fusion Proteins / metabolism
  • Sequence Deletion
  • Subcellular Fractions / metabolism

Substances

  • Fatty Acids, Unsaturated
  • Karyopherins
  • Leupeptins
  • Proteasome Inhibitors
  • Receptors, Cytoplasmic and Nuclear
  • Recombinant Fusion Proteins
  • enhanced green fluorescent protein
  • exportin 1 protein
  • Green Fluorescent Proteins
  • Protein Methyltransferases
  • Histone-Lysine N-Methyltransferase
  • SETDB1 protein, human
  • Proteasome Endopeptidase Complex
  • benzyloxycarbonylleucyl-leucyl-leucine aldehyde
  • leptomycin B