Epidermal growth factor

Epidermal growth factor (beta-urogastrone)
File:PBB Protein EGF image.jpg PDB rendering based on 1ivo.
Available structures PDB Ortholog search: Template:Homologene2PDBe PDBe, Template:Homologene2uniprot RCSB List of PDB id codes 1ivo​, 1jl9​, 1nql​, 1p9j​
Identifiers
Symbols	EGF ; URG
External IDs	Template:OMIM5 Template:MGI HomoloGene: 1483
Gene ontology Molecular function Template:GNF GO Template:GNF GO Template:GNF GO Template:GNF GO Cellular component Template:GNF GO Template:GNF GO Template:GNF GO Template:GNF GO Template:GNF GO Biological process Template:GNF GO Template:GNF GO Template:GNF GO Template:GNF GO Template:GNF GO Template:GNF GO Template:GNF GO Template:GNF GO
RNA expression pattern
More reference expression data
Orthologs
Template:GNF Ortholog box
Species	Human	Mouse
Entrez	n/a	n/a
Ensembl	n/a	n/a
UniProt	n/a	n/a
RefSeq (mRNA)	n/a	n/a
RefSeq (protein)	n/a	n/a
Location (UCSC)	n/a	n/a
PubMed search	n/a	n/a

Diagram showing key components of the MAPK/ERK pathway. In the diagram, "P" represents phosphate. Note EGF at the very top.

Epidermal growth factor or EGF is a growth factor that plays an important role in the regulation of cell growth, proliferation, and differentiation. Human EGF is a 6045-Da protein with 53 amino acid residues and three intramolecular disulfide bonds.

Function

EGF acts by binding with high affinity to epidermal growth factor receptor (EGFR) on the cell surface and stimulating the intrinsic protein-tyrosine kinase activity of the receptor (see the second diagram). The tyrosine kinase activity, in turn, initiates a signal transduction cascade that results in a variety of biochemical changes within the cell - a rise in intracellular calcium levels, increased glycolysis and protein synthesis, and increases in the expression of certain genes including the gene for EGFR - that ultimately lead to DNA synthesis and cell proliferation.

EGF-family

EGF is the founding member of the EGF-family of proteins. Members of this protein family have highly similar structural and functional characteristics. Besides EGF itself other family members include:

• Heparin-binding EGF-like growth factor (HB-EGF)
• transforming growth factor-α (TGF-α)
• Amphiregulin (AR)
• Epiregulin (EPR)
• Epigen
• Betacellulin (BTC)
• neuregulin-1 (NRG1)
• neuregulin-2 (NRG2)
• neuregulin-3 (NRG3)
• neureguline-4 (NRG4).

All family members contain one or more repeats of the conserved amino acid sequence:

CX₇CX_4-5CX_10-13CXCX₈GXRC

Where X represents any amino acid.

This sequence contains 6 cysteine residues that form three intramolecular disulphide bonds. Disulphide bond formation generates three structural loops that are essential for high-affinity binding between members of the EGF-family and their cell-surface receptors.

EGF as Therapeutic Protein

EGF is currently being marketed as a therapeutic protein for the treatment of diabetic foot ulcers by at least three companies. Bharat Biotech International, a company based in India, is marketing EGF as REGEN-D, Daewoong Pharmaceutical, based in South Korea, is marketing EGF as Easyef, and the Center for Genetic Engineering and Biotechnology, in Cuba, is marketing EGF as CITOPROT-P. EGF is also used in a burn treatment cream product, Hebermin, manufactured by Heber Biotec S. A. in Cuba.

External links

• EGF at the Human Protein Reference Database.
• Epidermal+growth+factor at the US National Library of Medicine Medical Subject Headings (MeSH)

Further reading

• Boonstra J, Rijken P, Humbel B; et al. (1995). "The epidermal growth factor". Cell Biol. Int. 19 (5): 413–30. PMID 7640657.CS1 maint: Explicit use of et al. (link) CS1 maint: Multiple names: authors list (link)
• Dvorak B (2004). "Epidermal growth factor and necrotizing enterocolitis". Clinics in perinatology. 31 (1): 183–92. doi:10.1016/j.clp.2004.03.015. PMID 15183666.
• Howell WM (2004). "Epidermal growth factor gene polymorphism and development of cutaneous melanoma". J. Invest. Dermatol. 123 (4): xx–xxi. doi:10.1111/j.0022-202X.2004.23308.x. PMID 15373802.