Epiregulin

Epiregulin (EPR) is a protein that in humans is encoded by the EREG gene.^[5][6]

EREG
Available structures PDB Ortholog search: PDBe RCSB List of PDB id codes 1K36, 1K37, 5E8D
Identifiers
Aliases	EREG, EPR, ER, Ep, epiregulin
External IDs	OMIM: 602061; MGI: 107508; HomoloGene: 1097; GeneCards: EREG; OMA:EREG - orthologs
Gene location (Human) Chr. Chromosome 4 (human)[1] Band 4q13.3 Start 74,365,145 bp[1] End 74,388,749 bp[1]
Gene location (Mouse) Chr. Chromosome 5 (mouse)[2] Band 5|5 E1 Start 91,222,481 bp[2] End 91,241,505 bp[2]
RNA expression pattern Bgee Human Mouse (ortholog) Top expressed in buccal mucosa cell amniotic fluid skin of thigh skin of arm human penis cervix epithelium oral cavity bone marrow cell skin of abdomen gums Top expressed in skin of external ear conjunctival fornix esophagus umbilical cord endothelial cell of lymphatic vessel tunica media of zone of aorta skin of back ileum cornea epidermis More reference expression data BioGPS n/a
Gene ontology Molecular function epidermal growth factor receptor binding protein binding growth factor activity protein tyrosine kinase activity phosphatidylinositol-4,5-bisphosphate 3-kinase activity Cellular component integral component of membrane membrane plasma membrane integral component of plasma membrane extracellular region intracellular anatomical structure extracellular space clathrin-coated vesicle membrane Biological process luteinizing hormone signaling pathway positive regulation of epidermal growth factor-activated receptor activity cell differentiation ovarian cumulus expansion negative regulation of smooth muscle cell differentiation positive regulation of cytokine production cytokine-mediated signaling pathway positive regulation of fibroblast proliferation cell-cell signaling anatomical structure morphogenesis response to peptide hormone wound healing mRNA transcription female meiotic nuclear division primary follicle stage keratinocyte differentiation MAPK cascade multicellular organism development positive regulation of DNA replication keratinocyte proliferation oocyte maturation angiogenesis positive regulation of cell population proliferation positive regulation of innate immune response negative regulation of epithelial cell proliferation animal organ morphogenesis positive regulation of phosphorylation negative regulation of transcription, DNA-templated positive regulation of mitotic nuclear division ovulation positive regulation of cell division negative regulation of cell population proliferation positive regulation of smooth muscle cell proliferation positive regulation of protein kinase activity ERBB2 signaling pathway regulation of cell motility epidermal growth factor receptor signaling pathway peptidyl-tyrosine phosphorylation phosphatidylinositol phosphate biosynthetic process positive regulation of protein kinase B signaling signal transduction negative regulation of epidermal growth factor receptor signaling pathway membrane organization Sources:Amigo / QuickGO
Orthologs 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: 74.37 – 74.39 Mb Chr 5: 91.22 – 91.24 Mb PubMed search [3] [4]
Wikidata
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Structure

Epiregulin consists of 46 amino acid residues. Its secondary structure contains approximately 30 percent of β-sheet in the strand.^[7] Some of the residues form loops and turns due to the hydrogen bonding.^[7] 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.^[7]

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.

Function

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.^[6] 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.^[7]