From Wikipedia, the free encyclopedia
Jump to: navigation, search
NMR Structure of Human Epiregulin: by scheme of amino acid.[1] SCOP 103561
Available structures
PDB Ortholog search: PDBe, RCSB
Symbols EREG ; ER
External IDs OMIM602061 MGI107508 HomoloGene1097 GeneCards: EREG Gene
Species Human Mouse
Entrez 2069 13874
Ensembl ENSG00000124882 ENSMUSG00000029377
UniProt O14944 Q61521
RefSeq (mRNA) NM_001432 NM_007950
RefSeq (protein) NP_001423 NP_031976
Location (UCSC) Chr 4:
75.23 – 75.25 Mb
Chr 5:
91.07 – 91.09 Mb
PubMed search [1] [2]

Epiregulin (EPR) is a protein that in humans is encoded by the EREG gene.[2][3]


Epiregulin consists of 46 amino acid residues. Its secondary structure contains approximately 30 percent of β-sheet in the strand.[1] Some of the residues form loops and turns due to the hydrogen bonding.[1] The percentage of β-sheet in epiregulin depends on the domain and the secondary structures that they occupy. The polymeric molecules of epiregulin has the formula weight of 5280.1 g/mol with a polypeptide(L), a polymer type.[1]

Structural motifs in most proteins have typical connections in an all β motif. Meaning that the polypeptide chains do not make a crossover connection or in so far as this type of connection has not been observed. Epiregulin is one of the proteins that occupies a typical connection in all β motif. Furthermore, as the structure of epiregulin forms a chain in an all β motif, it also forms β hairpin structural motif. A β hairpin is when the two adjacent anti-parallel β strands connected by a β-turn.


Epiregulin is a member of the epidermal growth factor family. Epiregulin can function as a ligand of epidermal growth factor receptor (EGFR), as well as a ligand of most members of the ERBB (v-erb-b2 oncogene homolog) family of tyrosine-kinase receptors.[3] The secondary structure at the C-terminus epiregulin is different from other epidermal growth factor family ligands because of the lack of hydrogen bonds. The structural difference at the C-terminus may provide an explanation for the reduced binding affinity of epiregulin to the ERBB receptors.[1]


  1. ^ a b c d e PDB 1K36; Sato K, Nakamura T, Mizuguchi M, Miura K, Tada M, Aizawa T, Gomi T, Miyamoto K, Kawano K (October 2003). "Solution structure of epiregulin and the effect of its C-terminal domain for receptor binding affinity". FEBS Lett. 553 (3): 232–8. doi:10.1016/S0014-5793(03)01005-6. PMID 14572630. 
  2. ^ Toyoda H, Komurasaki T, Uchida D, Morimoto S (August 1997). "Distribution of mRNA for human epiregulin, a differentially expressed member of the epidermal growth factor family". Biochem. J. 326 (1): 69–75. PMC 1218638. PMID 9337852. 
  3. ^ a b "Entrez Gene: epiregulin". 

Further reading[edit]

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