Chromosoma

, Volume 114, Issue 3, pp 183–192

Developmental regulation of Suz12 localization

Authors

  • Cecile C. de la Cruz
    • Department of Biochemistry and BiophysicsUniversity of California
  • Jia Fang
    • Department of Biochemistry and BiophysicsThe University of North Carolina
  • Kathrin Plath
    • Whitehead Institute for Biomedical Research
  • Kathleen A. Worringer
    • Department of Biochemistry and BiophysicsUniversity of California
  • Dmitri A. Nusinow
    • Department of Biochemistry and BiophysicsUniversity of California
  • Yi Zhang
    • Department of Biochemistry and BiophysicsThe University of North Carolina
    • Department of Biochemistry and BiophysicsUniversity of California
Research Article

DOI: 10.1007/s00412-005-0008-6

Cite this article as:
de la Cruz, C.C., Fang, J., Plath, K. et al. Chromosoma (2005) 114: 183. doi:10.1007/s00412-005-0008-6

Abstract

Chromatin modifications are among the epigenetic alterations essential for genetic reprogramming during development. The Polycomb group (PcG) gene family mediates chromatin modifications that contribute to developmentally regulated transcriptional silencing. Trimethylation of histone H3 on lysine 27, mediated by a PcG protein complex consisting of Eed, Ezh2, and Suz12, is integral in differentiation, stem cell self-renewal, and tumorigenesis. Eed and Ezh2 are also implicated in the developmentally regulated silencing of the inactive X chromosome, as they are transiently enriched on the inactive X chromosome when X chromosome silencing is initiated. Here we analyze the dynamic localization of Suz12 during cellular differentiation and X-inactivation. Though Suz12 is a requisite member of the Eed/Ezh2 complexes, we found that Suz12 exhibits a notable difference from Ezh2 and Eed: while Ezh2 and Eed levels decrease during stem cell differentiation, Suz12 levels remain constant. Despite the differential regulation in abundance of Suz12 and Eed/Ezh2, Suz12 is also transiently enriched on the Xi during early stages of X-inactivation, and this accumulation is Xist RNA dependent. These results suggest that Suz12 may have a function that is not mediated by its association with Eed and Ezh2, and that this additional function is not involved in the regulation of X-inactivation.

Supplementary material

412_2005_8_Fig8_ESM.gif (103 kb)

Levels of Suz12 remain constant throughout stem cell differentiation. a, b Immunostaining for Ezh2 (first column) and Eed (secong column) in (a) undifferentiated ES cells and (b) a transformed mouse fibroblast cell line. DAPI delianates the nucleus (third column) and the merge (fourth column) is an overlay of Ezh2 (green) and Eed (red). c, d Immunostaining for Suz12 (first column) and Eed (second column) in (c undifferentiated ES cells and (d a transformed mouse fibroblasts cell line. DAPI delineates the nucleus (third column) and the merge (fourth column) is an overlay of Suz12 (green) and Eed (red)

Copyright information

© Springer-Verlag 2005