Display Settings:

Format

Send to:

Choose Destination
See comment in PubMed Commons below
Genetics. 2007 Apr;175(4):1625-36. Epub 2007 Feb 4.

A balance between two nuclear localization sequences and a nuclear export sequence governs extradenticle subcellular localization.

Author information

  • 1Department of Genetics and Development, Columbia University, New York, New York 10032, USA.

Abstract

During animal development, transcription factor activities are modulated by several means, including subcellular localization. The Hox cofactor Extradenticle (Exd) has a dynamic subcellular localization, such that Exd is cytoplasmic by default, but is nuclear when complexed with another homeodomain protein, Homothorax (Hth). These observations raise the question of whether dimerization with Hth simply induces Exd's nuclear localization or, alternatively, if Hth is also necessary for Exd activity. To address this question, we analyzed the nuclear transport signals in Exd, including a divergent nuclear export signal (NES) and two nuclear localization signals (NLSs). We show that, although these signals are weak compared to canonical signals, they balance each other in Exd. We also provide evidence that Exd contains an NLS mask that contributes to its cytoplasmic localization. With these signals characterized, we generated forms of Exd that are nuclear localized in the absence of Hth. Surprisingly, although these Exd forms are functional, they do not phenocopy Hth overexpression. These findings suggest that Hth is required for Exd activity, not simply for inducing its nuclear localization.

PMID:
17277370
[PubMed - indexed for MEDLINE]
PMCID:
PMC1855138
Free PMC Article

Images from this publication.See all images (6)Free text

F igure  1.—
F igure  2.—
F igure  3.—
F igure  4.—
F igure  5.—
F igure  6.—
PubMed Commons home

PubMed Commons

0 comments
How to join PubMed Commons

    Supplemental Content

    Icon for HighWire Icon for PubMed Central
    Loading ...
    Write to the Help Desk