Multiple subnuclear targeting signals of the leukemia-related AML1/ETO and ETO repressor proteins

Karina Barseguian, Bart Lutterbach, Scott W. Hiebert, Jeffrey Nickerson, Jane B. Lian, Janet L. Stein, Andre J. Van Wijnen, Gary S. Stein

Research output: Contribution to journalArticle

49 Scopus citations

Abstract

Leukemic disease can be linked to aberrant gene expression. This often is the result of molecular alterations in transcription factors that lead to their misrouting within the nucleus. The acute myelogenous leukemia-related fusion protein AML1/ETO is a striking example. It originates from a gene rearrangement t(8;21) that fuses the N-terminal part of the key hematopoietic regulatory factor AML1 (RUNX1) to the ETO (MTG8) repressor protein. AML1/ETO lacks the intranuclear targeting signal of the wild-type AML1 and is directed by the ETO component to alternate nuclear matrix-associated sites. To understand this aberrant subnuclear trafficking of AML1/ETO, we created a series of mutations in the ETO protein. These were characterized biochemically by immunoblotting and in situ by immunofluorescence microscopy. We identified two independent subnuclear targeting signals in the N- and C-terminal regions of ETO that together direct ETO to the same binding sites occupied by AML1/ETO. However, each segment alone is targeted to a different intranuclear location. The N-terminal segment contains a nuclear localization signal and the conserved hydrophobic heptad repeat domain responsible for protein dimerization and interaction with the mSin3A transcriptional repressor. The C-terminal segment spans the nervy domain and the zinc finger region, which together support interactions with the corepressors N-CoR and HDACs. Our findings provide a molecular basis for aberrant subnuclear targeting of the AML1/ETO protein, which is a principal defect in t(8;21)-related acute myelogenous leukemia.

Original languageEnglish (US)
Pages (from-to)15434-15439
Number of pages6
JournalProceedings of the National Academy of Sciences of the United States of America
Volume99
Issue number24
DOIs
StatePublished - Nov 26 2002

ASJC Scopus subject areas

  • General

Fingerprint Dive into the research topics of 'Multiple subnuclear targeting signals of the leukemia-related AML1/ETO and ETO repressor proteins'. Together they form a unique fingerprint.

  • Cite this

    Barseguian, K., Lutterbach, B., Hiebert, S. W., Nickerson, J., Lian, J. B., Stein, J. L., Van Wijnen, A. J., & Stein, G. S. (2002). Multiple subnuclear targeting signals of the leukemia-related AML1/ETO and ETO repressor proteins. Proceedings of the National Academy of Sciences of the United States of America, 99(24), 15434-15439. https://doi.org/10.1073/pnas.242588499