HES1

Last updated
HES1
Available structures
PDB Ortholog search: PDBe RCSB
Identifiers
Aliases HES1 , HES-1, HHL, HRY, bHLHb39, hes family bHLH transcription factor 1
External IDs OMIM: 139605 MGI: 104853 HomoloGene: 38067 GeneCards: HES1
Orthologs
SpeciesHumanMouse
Entrez
Ensembl
UniProt
RefSeq (mRNA)

NM_005524

NM_008235

RefSeq (protein)

NP_005515

NP_032261

Location (UCSC) Chr 3: 194.14 – 194.14 Mb Chr 16: 29.88 – 29.89 Mb
PubMed search [3] [4]
Wikidata
View/Edit Human View/Edit Mouse

Transcription factor HES1 (hairy and enhancer of split-1) is a protein that is encoded by the Hes1 gene, and is the mammalian homolog of the hairy gene in Drosophila. [5] [6] HES1 is one of the seven members of the Hes gene family (HES1-7). Hes genes code nuclear proteins that suppress transcription. [7]

Contents

This protein belongs to the basic helix-loop-helix (bHLH) family of transcription factors. It is a transcriptional repressor of genes that require a bHLH protein for their transcription. The protein has a particular type of basic domain that contains a helix interrupting protein that binds to the N-box promoter region rather than the canonical enhancer box (E-box). [6] As a member of the bHLH family, it is a transcriptional repressor that influences cell proliferation and differentiation in embryogenesis. [7] HES1 regulates its own expression via a negative feedback loop, and oscillates with approximately 2-hour periodicity. [8]

Structure

There are three conserved domains in Hes genes that impart transcriptional functions: the bHLH domain, the Orange domain, and the WRPW motif. Hes genes differ from other bHLH factors in that they have a proline residue in the middle of the basic DNA binding region. This proline has been proposed to give Hes proteins unique DNA binding capacity. While most bHLH factors bind to the E-box consensus sequence (CANNTG) that is present in the promoter region of target genes, Hes factors bind more preferentially to the Class C site or N box (CACNAG). [7] The Orange domain serves to regulate the choice of bHLH heterodimer partners. [9] The C-terminal WRPW domain inhibits transcription. [10]

Interactions

Similarly to other HES proteins, Hes1 has been shown to interact with the co-repressors encoded by the Transducin-like E(spl) (TLE) genes and the Groucho-related gene (Grg), both homologs of the Drosophila groucho. [11] Because Groucho in Drosophila inhibits transcription by recruiting histone deacetylase, it is likely that a Hes-Groucho complex actively blocks transcription by disabling chromatin. Hes proteins also heterodimerize with bHLH repressors such as Hey1 and Hey2, a process which also blocks transcription. Hes factors also heterodimerize with bHLH activators such as E47, also known as Tcfe2a, and Mash1, also known as Ascl1, both of which are the mammalian homologs to proneural genes in Drosophila. The E47-Hes and Mash1-Hes heterodimer complexes cannot bind DNA, and therefore repress transcription. [7] Hes1 also interacts with TLE2 [12] and Sirtuin 1. [13]

HES1 and stem cells

HES1 influences the maintenance of certain stem cells and progenitor cells. Specifically, HES1 influences the timing of differentiation by repressing bHLH activators, and determines binary cell fate. HES1 has been shown to play a large role in both the nervous, and digestive systems. HES1 has been shown to influence these two systems partially through the Notch signaling pathway.

Neural development

HES1 is expressed in both neuroepithelial cells and radial glial cells, both neural stem cells. Hes1 expression, along with that of Hes5, covers the majority of the developing embryo at embryonic day 10.5. [14] After this point, expression of Hes1 is limited to the subventricular zone. In HES1 knockout (KO) mice, Mash1 is compensatorily upregulated, and neurogenesis is accelerated. Indeed, if the expression of Hes1, Hes3, and Hes5 genes is inhibited, the expression of proneural genes increases, and while neurogenesis is accelerated, neural stem cells become prematurely depleted. Contrariwise, if these HES genes are overexpressed, neurogenesis is inhibited. [15] Thus HES1 genes are only involved in maintaining, not creating, neural stem cells.

Additionally, HES1 can guide neural stem cells down one of two paths of differentiation. HES1 can maintain neural stem cells expressing Pax6, but leads cells that are Pax6-negative to an astrocyte differentiation fate. [16] Epigenetic modifications such as DNA methylation also influence HES1's ability to direct differentiation. Demethylation of HES1 target sites in the promoter region of astrocyte-specific genes hastens astrocyte differentiation. [15] The oscillatory nature of Hes1 expression has a role in determining differentiation fate as well. HES1-high embryonic stem cells that received a differentiation signal often adopted a mesodermal fate, while HES1-low cells that received a differentiation signal differentiated into neuronal cells. These results were confirmed using quantitative PCR which showed that HES1-high cells showed high levels of Brachyury and Fgf5 expression (both of which are expressed highly in mesodermal cell types) with comparatively low levels genes expressed in neural cells such as Nestin . By contrast, HES1-low cells showed high levels of expression of genes involved in neural induction and low levels of expression of genes involved in mesodermal differentiation. [17] Cycling HES1 levels also contribute to the maintenance of neural progenitor cells by regulating Neurogenin2 (Ngn2) and Dll1 oscillations. [18] Hes1 levels fluctuate at different frequencies in different parts of the central nervous system: HES1 is continuously expressed at high levels in the boundaries, but vacillates in the compartments. This suggests that alternating HES1 levels may prompt differences in characteristics between anatomical elements of the central nervous system. [7]

Interactions with the Notch pathway

HES1 also plays an important role in the Notch signaling pathway. [19] In the absence of Notch signaling, RBPJ inhibits the expression of HES1. After Notch signals have been processed within the cell, however, the plasma membrane releases the intracellular domain of Notch, which moves to the nucleus where it associates with RBPJ. The binding causes a conformational change which leads co-repressors to disassociate and allows co-activators to bind. The new activating complex then prompts HES1 expression. Notch signaling activates HES1 expression. HES1 has been shown to target at least Notch ligands: Dll1, Jagged1 (Jag1), and Neurogenin-2. [15] , [17] Dll1, as with other Notch ligands, has been shown to induce neural differentiation, and HES1 binding of Dll1 blocks neural differentiation and leads to the maintenance of the neural stem cells and neural progenitor cells. [20] Notch signaling also occurs in the intestinal crypt cells. Hyperactivated Notch causes a reduction in the number of secretory cell types (i.e. goblet cells, enteroendocrine cells, and Paneth cells). Deletion of the Notch pathway by removing the Notch expression controller, Rbpsuh, causes the production of nearly only goblet cells. [21]

Digestive system

HES1 has been shown to influence the differentiation decision of cells in the gastrointestinal tract. In pancreatic progenitor cells, HES1 expression inhibits the expression of Ptf1a, which controls exocrine cell differentiation, and Ngn3, which drives differentiation of endocrine cell types that will form the islets of Langerhans. [7] The absence of Hes1 in the developing intestine of mice promotes the increase of Math1 (a protein required for the production of intestinal secretory cell types), which leads to an increase of goblet, enteroendocrine, and Paneth cells. When Hes1 is deleted in mouse and zebrafish, surplus goblet cells and enteroendocrine cells are made while few enterocytes are made. [7] , [21] Liver progenitor cells differentiate into two different cell types: hepatocytes and biliary epithelial cells. When Hes1 expression is low, hepatocytes form normally, but bile ducts are completely absent. [22] This phenotype resembles Alagille syndrome, a hallmark of which is mutations in Jagged1. Therefore, Hes-Notch interactions also play a role in digestive organ development.

Related Research Articles

Escargot (esg) is a transcription factor expressed in Drosophila melanogaster. It is responsible for the maintenance of intestinal stem cells and is used as a marker for those types of cells in Drosophila. Apart from its expression in the gut, esg is also expressed in expressed in germline stem cells and cyst stem cells of the testis and, during development, in neural stem cells and imaginal disks.

Inhibitor of DNA-binding/differentiation proteins, also known as ID proteins comprise a family of proteins that heterodimerize with basic helix-loop-helix (bHLH) transcription factors to inhibit DNA binding of bHLH proteins. ID proteins also contain the HLH-dimerization domain but lack the basic DNA-binding domain and thus regulate bHLH transcription factors when they heterodimerize with bHLH proteins. The first helix-loop-helix proteins identified were named E-proteins because they bind to Ephrussi-box (E-box) sequences. In normal development, E proteins form dimers with other bHLH transcription factors, allowing transcription to occur. However, in cancerous phenotypes, ID proteins can regulate transcription by binding E proteins, so no dimers can be formed and transcription is inactive. E proteins are members of the class I bHLH family and form dimers with bHLH proteins from class II to regulate transcription. Four ID proteins exist in humans: ID1, ID2, ID3, and ID4. The ID homologue gene in Drosophila is called extramacrochaetae (EMC) and encodes a transcription factor of the helix-loop-helix family that lacks a DNA binding domain. EMC regulates cell proliferation, formation of organs like the midgut, and wing development. ID proteins could be potential targets for systemic cancer therapies without inhibiting the functioning of most normal cells because they are highly expressed in embryonic stem cells, but not in differentiated adult cells. Evidence suggests that ID proteins are overexpressed in many types of cancer. For example, ID1 is overexpressed in pancreatic, breast, and prostate cancers. ID2 is upregulated in neuroblastoma, Ewing’s sarcoma, and squamous cell carcinoma of the head and neck.

<span class="mw-page-title-main">Myogenesis</span> Formation of muscular tissue, particularly during embryonic development

Myogenesis is the formation of skeletal muscular tissue, particularly during embryonic development.

The scleraxis protein is a member of the basic helix-loop-helix (bHLH) superfamily of transcription factors. Currently two genes have been identified to code for identical scleraxis proteins.

An E-box is a DNA response element found in some eukaryotes that acts as a protein-binding site and has been found to regulate gene expression in neurons, muscles, and other tissues. Its specific DNA sequence, CANNTG, with a palindromic canonical sequence of CACGTG, is recognized and bound by transcription factors to initiate gene transcription. Once the transcription factors bind to the promoters through the E-box, other enzymes can bind to the promoter and facilitate transcription from DNA to mRNA.

The gene extramachrochaetae (emc) is a Drosophila melanogaster gene that codes for the Emc protein, which has a wide variety of developmental roles. It was named, as is common for Drosophila genes, after the phenotypic change caused by a mutation in the gene (macrochaetae are the longer bristles on Drosophila).

<span class="mw-page-title-main">TLE1</span> Protein-coding gene in the species Homo sapiens

Transducin-like enhancer protein 1 is a protein that in humans is encoded by the TLE1 gene.

<span class="mw-page-title-main">HEY1</span> Protein-coding gene in the species Homo sapiens

Hairy/enhancer-of-split related with YRPW motif protein 1 is a protein that in humans is encoded by the HEY1 gene.

<span class="mw-page-title-main">ASCL1</span> Protein-coding gene in humans

Achaete-scute homolog 1 is a protein that in humans is encoded by the ASCL1 gene. Because it was discovered subsequent to studies on its homolog in Drosophila, the Achaete-scute complex, it was originally named MASH-1 for mammalian achaete scute homolog-1.

<span class="mw-page-title-main">HEY2</span> Protein-coding gene in the species Homo sapiens

Hairy/enhancer-of-split related with YRPW motif protein 2 (HEY2) also known as cardiovascular helix-loop-helix factor 1 (CHF1) is a protein that in humans is encoded by the HEY2 gene.

<span class="mw-page-title-main">ID4</span> Protein-coding gene in humans

ID4 is a protein coding gene. In humans, it encodes for the protein known as DNA-binding protein inhibitor ID-4. This protein is known to be involved in the regulation of many cellular processes during both prenatal development and tumorigenesis. This is inclusive of embryonic cellular growth, senescence, cellular differentiation, apoptosis, and as an oncogene in angiogenesis.

<span class="mw-page-title-main">ATOH1</span> Protein-coding gene in the species Homo sapiens

Protein atonal homolog 1 is a protein that in humans is encoded by the ATOH1 gene.

<span class="mw-page-title-main">HES6</span> Protein-coding gene in the species Homo sapiens

Transcription cofactor HES-6 is a protein that in humans is encoded by the HES6 gene.

Neurogenins, often abbreviated as Ngn, are a family of bHLH transcription factors involved in specifying neuronal differentiation. The family consisting of Neurogenin-1, Neurogenin-2, and Neurogenin-3, plays a fundamental role in specifying neural precursor cells and regulating the differentiation of neurons during embryonic development. It is one of many gene families related to the atonal gene in Drosophila. Other positive regulators of neuronal differentiation also expressed during early neural development include NeuroD and ASCL1.

<span class="mw-page-title-main">HES5</span> Protein-coding gene in the species Homo sapiens

Transcription factor HES-5 is a protein that in humans is encoded by the HES5 gene.

<span class="mw-page-title-main">BHLHE41</span> Protein-coding gene in humans

"Basic helix-loop-helix family, member e41", or BHLHE41, is a gene that encodes a basic helix-loop-helix transcription factor repressor protein in various tissues of both humans and mice. It is also known as DEC2, hDEC2, and SHARP1, and was previously known as "basic helix-loop-helix domain containing, class B, 3", or BHLHB3. BHLHE41 is known for its role in the circadian molecular mechanisms that influence sleep quantity as well as its role in immune function and the maturation of T helper type 2 cell lineages associated with humoral immunity.

<span class="mw-page-title-main">Neurogenin-2</span> Protein-coding gene in the species Homo sapiens

Neurogenin-2 is a protein that in humans is encoded by the NEUROG2 gene.

Proneural genes encode transcription factors of the basic helix-loop-helix (bHLH) class which are responsible for the development of neuroectodermal progenitor cells. Proneural genes have multiple functions in neural development. They integrate positional information and contribute to the specification of progenitor-cell identity. From the same ectodermal cell types, neural or epidermal cells can develop based on interactions between proneural and neurogenic genes. Neurogenic genes are so called because loss of function mutants show an increase number of developed neural precursors. On the other hand, proneural genes mutants fail to develop neural precursor cells.

<span class="mw-page-title-main">Hes family bhlh transcription factor 2</span> Protein-coding gene in the species Homo sapiens

Hes family bHLH transcription factor 2 is a protein that in humans is encoded by the HES2 gene.

<span class="mw-page-title-main">HES7 gene</span> Protein-coding gene in humans

(HES7) or bHLHb37 is protein coding mammalian gene found on chromosome 17 in humans. HES7 is a member of the Hairy and Enhancer of Split families of Basic helix-loop-helix proteins. The gene product is a transcription factor and is expressed cyclically in the presomitic mesoderm as part of the Notch signalling pathway. HES7 is involved in the segmentation of somites from the presomitic mesoderm in vertebrates. The HES7 gene is self-regulated by a negative feedback loop in which the gene product can bind to its own promoter. This causes the gene to be expressed in an oscillatory manner. The HES7 protein also represses expression of Lunatic Fringe (LFNG) thereby both directly and indirectly regulating the Notch signalling pathway. Mutations in HES7 can result in deformities of the spine, ribs and heart. Spondylocostal dysostosis is a common disease caused by mutations in the HES7 gene. The inheritance pattern of Spondylocostal dysostosis is autosomal recessive.

References

  1. 1 2 3 GRCh38: Ensembl release 89: ENSG00000114315 - Ensembl, May 2017
  2. 1 2 3 GRCm38: Ensembl release 89: ENSMUSG00000022528 - Ensembl, May 2017
  3. "Human PubMed Reference:". National Center for Biotechnology Information, U.S. National Library of Medicine.
  4. "Mouse PubMed Reference:". National Center for Biotechnology Information, U.S. National Library of Medicine.
  5. Feder JN, Li L, Jan LY, Jan YN (Jul 1994). "Genomic cloning and chromosomal localization of HRY, the human homolog to the Drosophila segmentation gene, hairy". Genomics. 20 (1): 56–61. doi:10.1006/geno.1994.1126. PMID   8020957.
  6. 1 2 "Entrez Gene: HES1 hairy and enhancer of split 1, (Drosophila)".
  7. 1 2 3 4 5 6 7 Kageyama R, Ohtsuka T, Kobayashi T (2007). "The Hes gene family: Repressors and oscillators that orchestrate embryogenesis". Development. 134 (7): 1243–1251. doi:10.1242/dev.000786. PMID   17329370. S2CID   1693293.
  8. Hirata H, Yoshiura S, Ohtsuka T, Bessho Y, Harada T, Yoshikawa K, Kageyama R (October 2002). "Oscillatory Expression of the bHLH Factor Hes1 Regulated by a Negative Feedback Loop". Science . 298 (5594): 840–843. Bibcode:2002Sci...298..840H. doi:10.1126/science.1074560. PMID   12399594. S2CID   30725650.
  9. Taelman V, Van Wayenbergh R, Sölter M, Pichon B, Pieler T, Christophe D, Bellefroid EJ (2004). "Sequences downstream of the bHLH domain of the Xenopus hairy-related transcription factor-1 act as an extended dimerization domain that contributes to the selection of the partners". Developmental Biology. 276 (1): 47–63. doi: 10.1016/j.ydbio.2004.08.019 . PMID   15531363.
  10. Kang SA, Seol JH, Kim J (2005). "The conserved WRPW motif of Hes6 mediates proteasomal degradation". Biochemical and Biophysical Research Communications. 332 (1): 33–36. doi:10.1016/j.bbrc.2005.04.089. PMID   15896295.
  11. Paroush Z, Finley RL, Kidd T, Wainwright SM, Ingham PW, Brent R, Ish-Horowicz D (1994). "Groucho is required for Drosophila neurogenesis, segmentation, and sex determination and interacts directly with hairy-related bHLH proteins". Cell. 79 (5): 805–815. doi:10.1016/0092-8674(94)90070-1. PMID   8001118. S2CID   14574755.
  12. Grbavec D, Lo R, Liu Y, Stifani S (December 1998). "Transducin-like Enhancer of split 2, a mammalian homologue of Drosophila Groucho, acts as a transcriptional repressor, interacts with Hairy/Enhancer of split proteins, and is expressed during neuronal development". Eur. J. Biochem. 258 (2): 339–49. doi: 10.1046/j.1432-1327.1998.2580339.x . PMID   9874198.
  13. Takata T, Ishikawa F (January 2003). "Human Sir2-related protein SIRT1 associates with the bHLH repressors HES1 and HEY2 and is involved in HES1- and HEY2-mediated transcriptional repression". Biochem. Biophys. Res. Commun. 301 (1): 250–7. doi:10.1016/S0006-291X(02)03020-6. PMID   12535671.
  14. Hatakeyama J, Bessho Y, Katoh K, Ookawara S, Fujioka M, Guillemot F, Kageyama R (2004). "Hes genes regulate size, shape and histogenesis of the nervous system by control of the timing of neural stem cell differentiation". Development. 131 (22): 5539–5550. doi: 10.1242/dev.01436 . hdl: 2433/144732 . PMID   15496443.
  15. 1 2 3 Kageyama R, Ohtsuka T, Kobayashi T (2008). "Roles of Hes genes in neural development". Development, Growth & Differentiation. 50: S97–103. doi:10.1111/j.1440-169X.2008.00993.x. PMID   18430159. S2CID   25283902.
  16. Sugimori M, Nagao M, Bertrand N, Parras CM, Guillemot F, Nakafuku M (2007). "Combinatorial actions of patterning and HLH transcription factors in the spatiotemporal control of neurogenesis and gliogenesis in the developing spinal cord". Development. 134 (8): 1617–1629. doi:10.1242/dev.001255. PMID   17344230. S2CID   10018858.
  17. 1 2 Kobayashi T, Mizuno H, Imayoshi I, Furusawa C, Shirahige K, Kageyama R (2009). "The cyclic gene Hes1 contributes to diverse differentiation responses of embryonic stem cells". Genes & Development. 23 (16): 1870–1875. doi:10.1101/gad.1823109. PMC   2725939 . PMID   19684110.
  18. Shimojo H, Ohtsuka T, Kageyama R (2008). "Oscillations in Notch Signaling Regulate Maintenance of Neural Progenitors". Neuron. 58 (1): 52–64. doi:10.1016/j.neuron.2008.02.014. hdl: 2433/135871 . PMID   18400163. S2CID   870946.
  19. Kageyama R, Ohtsuka T (1999). "The Notch-Hes pathway in mammalian neural development". Cell Research. 9 (3): 179–188. doi: 10.1038/sj.cr.7290016 . PMID   10520600. S2CID   12570403.
  20. Lowell S, Benchoua A, Heavey B, Smith AG (2006). "Notch Promotes Neural Lineage Entry by Pluripotent Embryonic Stem Cells". PLOS Biology. 4 (5): e121. doi: 10.1371/journal.pbio.0040121 . PMC   1431581 . PMID   16594731.
  21. 1 2 Crosnier C, Stamataki D, Lewis J (2006). "Organizing cell renewal in the intestine: Stem cells, signals and combinatorial control". Nature Reviews Genetics. 7 (5): 349–359. doi:10.1038/nrg1840. PMID   16619050. S2CID   37382174.
  22. Kodama Y, Hijikata M, Kageyama R, Shimotohno K, Chiba T (2004). "The role of notch signaling in the development of intrahepatic bile ducts". Gastroenterology. 127 (6): 1775–1786. doi:10.1053/j.gastro.2004.09.004. hdl: 2433/144718 . PMID   15578515.

Further reading

This article incorporates text from the United States National Library of Medicine, which is in the public domain.