Signaling protein; growth factor
EGF
EGF is epidermal growth factor, a protein distinct from its receptor, EGFR. Structural and cellular studies distinguish ligand recognition, receptor association and intracellular transport; these observations do not measure tissue repair.
This is a research reference, not a product offered in the Asciende catalog. Published studies do not establish the identity, purity or availability of a commercial preparation.
Protein, preparation and functional assay
Preserve the particular preparation and assay. Declared mass does not substitute for measured activity, and a protein name does not resolve all its forms.
- Which isoform, chain length and preparation were investigated?
- Are identity and, where relevant, an activity determination documented?
- Does the response arise from the isolated compound or a combination and its vehicle?
Mechanism described in the literature
Structural studies of human EGF and extracellular EGFR regions showed direct contacts between associated receptors. In vitro cellular models also linked internalized receptor fate to the duration of some signals. Structure and trafficking provide complementary explanations with different scopes.
Other names in the literature
- Epidermal growth factor
What a complex structure reveals
The 2002 study combined crystallography and mutagenesis to examine EGF–EGFR organization. Association includes a receptor-receptor interface; imagining the ligand only as a bridge between two proteins is insufficient. The extracellular-region structure does not alone represent the complete receptor inside a cell (PMID 12297050).
Internalization does not automatically mean degradation
In the 2008 in vitro systems, clathrin-mediated EGFR entry was associated with recycling and persistent signaling, while another route favored degradation. Less surface receptor is therefore not automatically an extinguished signal. Receptor distribution must be interpreted with time and transport route (PMID 18694561).
Identify what is being compared
An EGF preparation, an extracellular EGFR fragment and an EGFR-expressing cell are different materials. Retain each component and the readout: molecular association, localization or signaling. None alone demonstrates a change in organ function.
Questions and answers
Are EGF and EGFR names for the same material?
No. EGF is the protein ligand; EGFR is the receptor studied.
Does receptor entry into the cell mean signaling has stopped?
Not necessarily. The cited cellular models showed different consequences for different internalization routes.
Sources
- Crystal structure of the complex of human epidermal growth factor and receptor extracellular domains. — Cell, 2002
- Crystal structure of the complex of human epidermal growth factor and receptor extracellular domains.
- Clathrin-mediated internalization is essential for sustained EGFR signaling but dispensable for degradation. — Dev Cell, 2008
- Clathrin-mediated internalization is essential for sustained EGFR signaling but dispensable for degradation.