High impact information on HHEX

• Through this interaction, PRH inhibits eIF4E-dependent mRNA transport and subsequent transformation [1].
• Two candidate enhancers discovered in this way were located in intron 1 of the Fli-1 and PRH/Hex genes, both transcription factors previously implicated in controlling blood and endothelial development [2].
• Here we demonstrate that the proline-rich N-terminal domain of PRH binds to TLE1 in vitro and in yeast two-hybrid assays [3].
• Finally, we show that a mutation in the PRH N-terminal domain that blocks the PRH-TLE1 interaction in vitro eliminates co-repression [3].
• The proline-rich homeodomain protein (PRH/Hex) is important in the control of cell proliferation and differentiation and in the regulation of multiple processes in embryonic development [3].

Biological context of HHEX

• Genomic organization and chromosome mapping of the human homeobox gene HHEX [4].
• We discuss these results in terms of the roles of PRH and TLE in cell differentiation and development [3].
• The PRH homeodomain represses transcription by binding to TATA box sequences, whereas the proline-rich N-terminal domain of PRH can repress transcription when attached to a heterologous DNA-binding domain [3].
• Within the first region of deletion at 10q23.33-10q24.1, around microsatellite marker D10S185 (2.77 Mb), 23 genes were identified, including three (KIF11, HHEX, and HELLS) with functions that, if dysregulated, could be critical in MF and SS [5].
• We discuss these findings in terms of the biological role of PRH in gene regulation and the control of cell proliferation [6].

Anatomical context of HHEX

• Using yeast two-hybrid screening, we identified hematopoietically expressed homeobox (Hex) as a GATA-binding partner in endothelial cells [7].
• Northern blot hybridization indicates that PRH is preferentially expressed in myeloid and liver cells [8].
• Using degenerate oligonucleotide primers corresponding to conserved homeobox sequences in the polymerase chain reaction (PCR), we cloned from the HL60 promyelocytic cell line a homeobox gene we now designate PRH [8].
• Homeobox protein Hex facilitates serum responsive factor-mediated activation of the SM22alpha gene transcription in embryonic fibroblasts [9].

Associations of HHEX with chemical compounds

• We also directly analysed HMPH, an active free hydrazine form of genotoxic agaritine, and obtained direct evidence of its absence from mushrooms [10].
• A new method with good sensitivity and specificity for detecting and quantifying genotoxic hydrazines, agaritine and 4-(hydroxymethyl)phenylhydrazine (HMPH), was developed using liquid chromatography-electrospray tandem mass spectrometry (MS) [10].

Other interactions of HHEX

• In the present study, we report the genomic reconstruction of the human homeobox-containing gene HHEX by the use of the data available in public databases [4].

Analytical, diagnostic and therapeutic context of HHEX

• We show that PRH and TLE proteins are co-expressed in hematopoietic cells and interact in co-immunoprecipitation assays [3].
• PCR cloning of an orphan homeobox gene (PRH) preferentially expressed in myeloid and liver cells [8].
• Here, we show using a variety of techniques including gel-filtration, analytical ultracentrifugation, electron microscopy and in vitro cross-linking, that purified recombinant PRH is oligomeric and we use in vivo cross-linking to confirm that this protein exists as oligomers in cells [11].
• The majority of cases of per rectal haemorrhage (PRH) are due to colorectal causes within the diagnostic reach of the colonoscope [12].

References