Analysis of the subcellular localization of the human histone methyltransferase SETDB1

Keisuke Tachibana; Eiko Gotoh; Natsuko Kawamata; Kenji Ishimoto; Yoshie Uchihara; Hiroko Iwanari; Akira Sugiyama; Takeshi Kawamura; Yasuhiro Mochizuki; Toshiya Tanaka; Juro Sakai; Takao Hamakubo; Tatsuhiko Kodama; Takefumi Doi

doi:10.1016/j.bbrc.2015.08.065

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.

Authors

Affiliations

¹ Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka 565-0871, Japan. Electronic address: nya@phs.osaka-u.ac.jp.
² Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka 565-0871, Japan.
³ Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka 565-0871, Japan; Laboratory for System Biology and Medicine, Research Center for Advanced Science and Technology, The University of Tokyo, 4-6-1 Komaba, Meguro, Tokyo 153-8904, Japan.
⁴ Department of Quantitative Biology and Medicine, Research Center for Advanced Science and Technology, The University of Tokyo, 4-6-1 Komaba, Meguro, Tokyo 153-8904, Japan.
⁵ Radioisotope Center, The University of Tokyo, 2-11-16 Yayoi, Bunkyo, Tokyo 113-0032, Japan.
⁶ Laboratory for System Biology and Medicine, Research Center for Advanced Science and Technology, The University of Tokyo, 4-6-1 Komaba, Meguro, Tokyo 153-8904, Japan.
⁷ Division of Metabolic Medicine, Research Center for Advanced Science and Technology, The University of Tokyo, 4-6-1 Komaba, Meguro, Tokyo 153-8904, Japan.
⁸ Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka 565-0871, Japan. Electronic address: doi@phs.osaka-u.ac.jp.

PMID: 26296461
DOI: 10.1016/j.bbrc.2015.08.065

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
Exportin 1 Protein
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
Green Fluorescent Proteins
Protein Methyltransferases
Histone-Lysine N-Methyltransferase
SETDB1 protein, human
Proteasome Endopeptidase Complex
benzyloxycarbonylleucyl-leucyl-leucine aldehyde
leptomycin B