Hemoglobin subunit epsilon (HBE1)

The protein contains 147 amino acids for an estimated molecular weight of 16203 Da.

 

The epsilon chain is a beta-type chain of early mammalian embryonic hemoglobin. (updated: March 4, 2015)

Protein identification was indicated in the following studies:

  1. Goodman and co-workers. (2013) The proteomics and interactomics of human erythrocytes. Exp Biol Med (Maywood) 238(5), 509-518.
  2. Lange and co-workers. (2014) Annotating N termini for the human proteome project: N termini and Nα-acetylation status differentiate stable cleaved protein species from degradation remnants in the human erythrocyte proteome. J Proteome Res. 13(4), 2028-2044.
  3. Hegedűs and co-workers. (2015) Inconsistencies in the red blood cell membrane proteome analysis: generation of a database for research and diagnostic applications. Database (Oxford) 1-8.
  4. Wilson and co-workers. (2016) Comparison of the Proteome of Adult and Cord Erythroid Cells, and Changes in the Proteome Following Reticulocyte Maturation. Mol Cell Proteomics. 15(6), 1938-1946.
  5. D'Alessandro and co-workers. (2017) Red blood cell proteomics update: is there more to discover? Blood Transfus. 15(2), 182-187.
  6. Chu and co-workers. (2018) Quantitative mass spectrometry of human reticulocytes reveal proteome-wide modifications during maturation. Br J Haematol. 180(1), 118-133.

Methods

The following articles were analysed to gather the proteome content of erythrocytes.

The gene or protein list provided in the studies were processed using the ID mapping API of Uniprot in September 2018. The number of proteins identified and mapped without ambiguity in these studies is indicated below.
Only Swiss-Prot entries (reviewed) were considered for protein evidence assignation.

PublicationIdentification 1Uniprot mapping 2Not mapped /
Obsolete
TrEMBLSwiss-Prot
Goodman (2013)2289 (gene list)227853205992269
Lange (2014)123412347281224
Hegedus (2015)2638262202352387
Wilson (2016)165815281702911068
d'Alessandro (2017)18261817201815
Bryk (2017)20902060101081942
Chu (2018)18531804553621387

1 as available in the article and/or in supplementary material
2 uniprot mapping returns all protein isoforms as one entry

The compilation of older studies can be retrieved from the Red Blood Cell Collection database.

The data and differentiation stages presented below come from the proteomic study and analysis performed by our partners of the GReX consortium, more details are available in their published work.

No sequence conservation computed yet.

Interpro domains
Total structural coverage: 99%
Model score: 100

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No binding partner found

The reference OMIM entry for this protein is 142100

Hemoglobin--epsilon locus; hbe1

The epsilon locus determines the epsilon, or non-alpha, chain of embryonic hemoglobin (originally known as Gower-2). No mutations affecting the epsilon chain have yet been identified. Gower-1 is a tetramer of epsilon chains. The epsilon locus may be linked to the delta-beta complex. The amino acid sequence of the epsilon chain is similar to those of the delta and beta chains. Furthermore, the homologous chain in the mouse is linked to the beta locus (Gilman and Smithies, 1968). Shen and Smithies (1982) determined the complete nucleotide sequence of the 3.4-kb stretch of DNA 5-prime to the epsilon gene where a pseudogene (psi-beta-2) was thought to reside (Fritsch et al., 1980). They concluded that no globin-related gene exists there and provided a possible explanation for the earlier contrary conclusion. By studies in transgenic mice, Raich et al. (1992) demonstrated that deletion of a 'negative element' located between -182 and -467 bp upstream of the HBE gene cap site resulted in continuation of HBE gene expression in the definitive erythroblasts of the fetal liver and in the red blood cells of adult animals. The findings provided direct in vivo evidence that cis-acting silencing elements are involved in the developmental control of the HBE gene. Bailey et al. (1992) used the epsilon-globin gene to examine the debate as to whether all bats fall into a monophyletic order (Chiroptera) or have diphyletic origins with the megabats actually being 'flying primates.' Results of parsimony analysis supported bat monophyly. He and Russell (2002) analyzed the anti-sickling properties of HBE both in vitro as well as in vivo in a well-established mouse model of sickle cell anemia (603903). These animals, expressing 100% of human Hb S (141900.0243), display a chronic hemolytic anemia with compensatory marrow and extramedullary erythropoiesis, abundant circulating sickled erythrocytes, and chronic tissue damage evidenced by parallel histopathologic and functional deficits. By comparison, related mice that coexpress Hb S as well as HBE exhibited normal physiologic, morphologic, histologic, and functional attributes. Subsequent in vitro analyses substantiated results from whole-animal studies, indicating that the polymerization of deoxygenated Hb S can be significantly slowed by relatively small quantities of HBE. Together, the in vivo and in vitro analyses suggested that reactivation of epsilon-globin gene expression would be therapeutically beneficial to adults with sickle phenotypes, and provide a rationale for detailed investigations into the molecular basis for its developmental silencing. ... More on the omim web site

Subscribe to this protein entry history

May 12, 2019: Protein entry updated
Automatic update: model status changed

Nov. 17, 2018: Protein entry updated
Automatic update: model status changed

Feb. 2, 2018: Protein entry updated
Automatic update: Uniprot description updated

Dec. 19, 2017: Protein entry updated
Automatic update: Uniprot description updated

Nov. 23, 2017: Protein entry updated
Automatic update: Uniprot description updated

June 20, 2017: Protein entry updated
Automatic update: comparative model was added.

March 16, 2016: Protein entry updated
Automatic update: OMIM entry 142100 was added.

Feb. 25, 2016: Protein entry updated
Automatic update: model status changed