Nuclear Translocation of Extradenticle Requires homothorax , which Encodes an Extradenticle-Related Homeodomain Protein

@article{Rieckhof1997NuclearTO,
  title={Nuclear Translocation of Extradenticle Requires homothorax , which Encodes an Extradenticle-Related Homeodomain Protein},
  author={G. Rieckhof and F. Casares and H. Ryoo and M. Abu-Shaar and R. Mann},
  journal={Cell},
  year={1997},
  volume={91},
  pages={171-183}
}
We show that homothorax (hth) is required for the Hox genes to pattern the body of the fruit fly, Drosophila melanogaster. hth is necessary for the nuclear localization of an essential HOX cofactor, Extradenticle (EXD), and encodes a homeodomain protein that shares extensive identity with the product of Meis1, a murine proto-oncogene. MEIS1 is able to rescue hth mutant phenotypes and can induce the cytoplasmic-to-nuclear translocation of EXD in cell culture and Drosophila embryos. Thus, Meis1… Expand
The Homothorax homeoprotein activates the nuclear localization of another homeoprotein, extradenticle, and suppresses eye development in Drosophila.
TLDR
The cloning of the Drosophila homothorax (hth) gene is reported, a homolog of the mouse Meis1 proto-oncogene that has a homeobox related to that of exd that suggests that hth and exd function in the same pathway. Expand
Mutational analysis of the Drosophila homothorax gene.
TLDR
Observations may suggest that driving nuclear localization of EXD is the main role of HTH in patterning the embryonic PNS and that homeodomain-defective HTH protein retains some of its transcription-regulating functions by binding DNA via its interaction with EXD. Expand
A conformational change in PBX1A is necessary for its nuclear localization.
TLDR
It is proposed that MEIS family proteins induce a conformational change in PBX that unmasks the NLS, leading to nuclear localization and increased DNA-binding activity. Expand
Regulation of Hox target genes by a DNA bound Homothorax/Hox/Extradenticle complex.
TLDR
It is shown that a conserved N-terminal domain of HTH directly binds to EXD in vitro, and is sufficient to induce the nuclear localization ofEXD in vivo, however, mutating a key DNA binding residue in the HTH homeodomain abolishes many of its in vivo functions. Expand
Genetic evidence for the transcriptional-activating function of Homothorax during adult fly development.
TLDR
The HTH antimorph described in this work presents a new means by which the transcriptional activity of the endogenous HTH protein can be blocked in an inducible fashion in any desired cells or tissues without interfering with nuclear localization of EXD. Expand
Distinct functions of homeodomain-containing and homeodomain-less isoforms encoded by homothorax.
TLDR
It is found that many of hth's functions, including PD patterning and most Hox-related activities, can be executed by the HDless isoforms, suggesting that homeodomain-less variants of this gene family are evolutionarily ancient. Expand
Transcriptional activation by extradenticle in the Drosophila visceral mesoderm.
TLDR
It is demonstrated that nuclear EXD is more extensively phosphorylated than the cytoplasmic form, suggesting thatEXD is a target of signal transduction by protein kinases. Expand
Chromosomal binding sites of the homeotic cofactor Homothorax
TLDR
Interestingly, Hth accumulates at high levels in some of the most prominent hormone-induced chromosomal puffs, pointing to a possible role of Hth in activation of ecdysone-induced targets. Expand
A unique Extradenticle recruitment mode in the Drosophila Hox protein Ultrabithorax
TLDR
This finding highlights that the Hoxprotein Ubx has multiple ways to interact with the Exd cofactor and suggests that flexibility in Hox–PBC contacts contributes to specify and diversify Hox protein function. Expand
Functional dissection of the splice variants of the Drosophila gene homothorax (hth).
TLDR
This work demonstrates that hth is a complex gene that should not be considered as a functional unit and shows that during normal embryonic development not all the Hth isoforms translocate Exd into the nucleus, suggesting that both the proteins can also function separately. Expand
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