Hematopoietically-expressed homeobox protein HHEX (HHEX)

Hematopoietically-expressed homeobox protein HHEX (HHEX) is a member of the homeobox family of transcription factors, which are characterized by a conserved homeodomain responsible for sequence-specific DNA binding[1][2][3][4]. HHEX functions both as a transcriptional repressor and activator, involved in diverse biological processes such as embryonic patterning (notably head, liver, thyroid, heart, vasculature, forebrain), regulation of hematopoietic stem/progenitor cell fate, and cellular proliferation[1][2][4]. It plays a central role in the regulation of gene expression during development and adult hematopoiesis, in part by controlling cell cycle genes and influencing growth factor signaling pathways[2][3][4]. HHEX operates through protein-protein interactions and oligomerization, and is capable of repressing or activating target genes depending on cofactors and cellular context[4]. Aberrations in HHEX expression or function contribute to various diseases, including hematologic malignancies (as oncogene or tumor suppressor), diabetes, and congenital defects[3][4]. There are currently no reported drugs directly targeting HHEX, and its dual roles in cancer and development underscore significant therapeutic and safety challenges[4].

Other names

Proline-rich homeodomain proteinPRHPRHXHEXHOX11L-PENHomeobox protein HEXHomeobox protein PRHProline-rich homeodomain-containing transcription factorhematopoietically expressed homeobox

Transcriptional repression (e.g., repression of Cdkn2a via PRC2 complex), Transcriptional activation (e.g., WNT-mediated transcription), Modulation of mRNA export, Regulation of developmental gene expression