| HEY1 Gene | |
|---|---|
| Gene Symbol | HEY1 |
| Full Name | Hairy/Enhancer-of-Split Related with YRPW Motif 1 |
| Chromosome | 8q21.13 |
| NCBI Gene ID | [23493](https://www.ncbi.nlm.nih.gov/gene/23493) |
| OMIM | 605253 |
| Ensembl ID | ENSG00000164690 |
| UniProt ID | [Q9UQV3](https://www.uniprot.org/uniprot/Q9UQV3) |
| Associated Diseases | [Alzheimer's Disease](/diseases/alzheimers-disease); [Parkinson's Disease](/diseases/parkinsons-disease); Cardiovascular Malformations; Neurodevelopmental Disorders |
HEY1 (Hairy/Enhancer-of-Split Related with YRPW Motif 1) is a basic helix-loop-helix-Orange (bHLH-O) transcriptional regulator that functions as a key effector of Notch signaling. HEY1 is induced by Notch receptor activation and regulates downstream target genes involved in cell fate determination, differentiation, tissue morphogenesis, and cellular homeostasis. As a member of the Hairy and Enhancer of Split (HES/HEY) family, HEY1 plays critical roles in nervous system development and has been implicated in Alzheimer's Disease, Parkinson's Disease, and various neurodevelopmental and cardiovascular disorders. [1]
Unlike classical HES proteins that function primarily as transcriptional repressors, HEY1 possesses both repressor and activator functions depending on cellular context. The HEY family proteins (HEY1, HEY2, HEYL) represent evolutionary conserved effectors of Notch signaling that integrate Notch pathway activity with other developmental signaling pathways including Wnt, Hedgehog, and BMP. [2]
The HEY1 gene (ENSG00000164690) is located on chromosome 8q21.13 and encodes a protein of approximately 299 amino acids with a molecular weight of ~33 kDa. Like other bHLH-O family members, HEY1 contains several conserved functional domains:
| Domain | Position | Function |
|---|---|---|
| bHLH domain | aa 43-95 | DNA binding; dimerization with other bHLH proteins |
| Orange domain | aa 107-149 | Protein-protein interactions; transcriptional regulation |
| TEA domain | aa 1-30 | Transcriptional activation (in some contexts) |
| YRPW motif | aa 191-237 | Co-repressor recruitment; protein interactions |
| C-terminal tetrapeptide | aa 270-273 | Groucho/TLE co-repressor binding |
The bHLH domain enables HEY1 to bind the canonical E-box motif (CANNTG) as either homodimers or heterodimers with other bHLH proteins such as HES1, HES5, or Tisch (TNC). The Orange domain mediates specific protein-protein interactions that distinguish HEY1 from HES family members. The YRPW motif (also found in HEY2 and HEYL) allows HEY1 to recruit transcriptional co-repressors including Groucho/TLE family proteins, histone deacetylases (HDACs), and other chromatin modifiers. [3]
HEY1 is a direct transcriptional target of Notch receptor signaling. The canonical pathway proceeds as follows:
HEY1 then regulates downstream target genes involved in cell fate decisions, maintaining progenitor cell pools, and directing differentiation programs. [4]
Unlike HES proteins that maintain progenitor identity through lateral inhibition, HEY1 often functions in different contexts:
The functional diversity of HEY1 reflects its ability to recruit different co-factors depending on cellular context, making it a flexible effector of Notch signaling. [5]
HEY1 integrates Notch signaling with multiple developmental pathways:
This cross-talk enables HEY1 to coordinate complex developmental programs and cellular responses. [6]
HEY1 plays critical roles in neuronal development:
During cortical development, HEY1 is expressed in the ventricular zone and subventricular zone, where it helps coordinate the balance between progenitor proliferation and neuronal differentiation. Altered HEY1 expression disrupts this balance, potentially leading to neurodevelopmental disorders. [2:1]
In adult neurogenic niches (subventricular zone, dentate gyrus), HEY1 continues to regulate neural stem cell behavior:
HEY1 shows distinct expression patterns in the developing and adult brain:
| Brain Region | Expression Level | Cell Types |
|---|---|---|
| Cerebral Cortex | Moderate | Neural progenitors, some neurons |
| Hippocampus | Moderate | Dentate gyrus progenitors, CA1 neurons |
| Subventricular Zone | High | Neural stem cells |
| Cerebellum | Moderate | Granule cell progenitors |
| Basal Ganglia | Low-Moderate | Striatal neurons |
HEY1 dysfunction contributes to Alzheimer's Disease through multiple mechanisms:
Therapeutic targeting of Notch-HEY1 signaling is being explored to enhance neurogenesis in AD models. [7]
In Parkinson's Disease, HEY1 plays complex roles:
Studies show that Notch signaling activation can be protective or detrimental depending on context, highlighting the complexity of HEY1 function in PD. [8]
HEY1 was originally identified as critical for cardiovascular development:
Altered HEY1 expression or function is associated with:
The Notch-HEY1 axis represents a therapeutic target:
HEY1 expression may serve as a biomarker for:
Bray SJ. Notch signaling in context. Nat Rev Mol Cell Biol. 2016. ↩︎
Chiba S. Notch signaling in stem cell biology. World J Stem Cells. 2018. ↩︎ ↩︎
Kovall RA, et al. Structure and function of the Notch intracellular domain. J Mol Biol. 2018. ↩︎
Nakagawa O, et al. HEY1 and HEY2 as Notch targets. Development. 2004. ↩︎
Fischer A, et al. The Notch target genes Hey1 and Hey2. Dev Biol. 2004. ↩︎
Song J, et al. HEY family in cancer and neurodegeneration. Cell Mol Neurobiol. 2021. ↩︎
Anderson AE, et al. Notch signaling in Alzheimer's disease. Exp Neurol. 2011. ↩︎
Zheng Y, et al. Notch signaling in Parkinson's disease. J Mol Neurosci. 2022. ↩︎