Zinc fingers function cooperatively with KRAB domain for nuclear localization of KRAB-containing zinc finger proteins

PLoS One. 2014 Mar 19;9(3):e92155. doi: 10.1371/journal.pone.0092155. eCollection 2014.

Abstract

Multiple nuclear localization domains have been identified in nuclear proteins, and they finely control nuclear import and functions of those proteins. ZNF268 is a typical KRAB-containing zinc finger protein (KRAB-ZFP), and previous studies have shown that the KRAB domain reinforces nuclear localization of KRAB-ZFPs by interacting with KAP1. In this study, we find that some of 24 zinc fingers of ZNF268 also possess nuclear localization activity. Results of mutagenesis studies suggest that KRAB and zinc fingers are both necessary, and they function both independently and cooperatively for the nuclear localization of ZNF268. However, the subnuclear targeting activities of KRAB and zinc fingers are different. KRAB targets proteins in nucleoplasm, but not in the nucleolus, which is mediated by interaction with KAP1, while zinc fingers target proteins in the whole nucleus uniformly. The cooperative activities of KAP1-KRAB-zinc fingers result in the precise nucleoplasmic, but not nucleolar localization of KRAB-ZFPs. Our studies reveal a novel mechanism for the subcellular localization of KRAB-ZFPs and may help us to further explore their biological functions.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cell Nucleolus / metabolism
  • Cell Nucleus / metabolism*
  • HeLa Cells
  • Humans
  • Karyopherins / metabolism
  • Mutant Proteins / metabolism
  • Mutation / genetics
  • Nuclear Localization Signals
  • Nuclear Proteins / chemistry*
  • Nuclear Proteins / metabolism*
  • Protein Binding
  • Protein Structure, Tertiary
  • Protein Transport
  • Structure-Activity Relationship
  • Zinc Fingers*

Substances

  • Karyopherins
  • Mutant Proteins
  • Nuclear Localization Signals
  • Nuclear Proteins

Grants and funding

This work was supported by National High Technology Research and Development Program of China (863 Program) Grant 2006AA02A306, National Natural Science Foundation of China Grants 30871245 and 31271511. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.