Identification of heterochromatin protein 1 (HP1) as a phosphorylation target by Pim‐1 kinase and the effect of phosphorylation on the transcriptional repression function of HP1 1

FEBS Letters

Koike, Naoyuki²  Taira, Takahiro²  Iguchi-Ariga, Sanae M.M.¹  Ariga, Hiroyoshi²  Maita, Hiroshi² 

[1] College of Medical Technology, Hokkaido University, Kita-ku, Sapporo 060-0812, Japan;Department of Molecular Biology, Graduate School of Pharmaceutical Sciences, Hokkaido University, Kita 12, Nishi 6, Kita-ku, Sapporo 060-0812, Japan

关键词: Heterochoromatin protein 1;    Phosphorylation;    Pim-1;    HP1;    heterochoromatin protein 1;    HA;    hemagglutinin antigen;    GST;    glutathione-S-transferase;   

DOI  :  10.1016/S0014-5793(00)01105-4

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Pim-1, a protooncogene product, is a serine/threonine kinase and is thought to play a role in signal transduction in blood cells. Few phosphorylated target proteins for Pim-1, however, have been identified. In the present study, two-hybrid screening to clone cDNAs encoding proteins binding to Pim-1 was carried out, and a cDNA for heterochromatin protein 1γ (HP1γ) was obtained. Binding assays both in yeast and in vitro pull-down using the purified HP1γ and Pim-1 expressed in Escherichia coli showed that Pim-1 directly bound to the chromo shadow domain of HP1γ. HP1γ was also associated with Pim-1 in human HeLa cells and the serine clusters located at the center of HP1γ were phosphorylated by Pim-1 in vitro. Furthermore, a transcription repression activity of HP1γ was further stimulated by the deletion of the serine clusters targeted by Pim-1. These results suggest that Pim-1 affects the structure or silencing of chromatin by phosphorylating HP1.

【 授权许可】

Unknown