Epidermal growth factor precursor homology domain

All of the growth factors characterized so far are proteins (table 24.7). Many of them are cleaved from larger precursors. The 53-amino-acid epidermal growth factor (EGF) is cleaved from a precursor of 1,168 amino acids. This precursor is a membrane-spanning protein, with the EGF moiety and nine related sequences in the extracellular domain. EGF is homologous to several other growth factors,... 

Schematic representation of human LDL receptor showing five domains. The receptor mediates internalization of LDL and IDL by specific interaction of their B-lOO and E apoprotein moieties with two cysteine-rich negatively charged areas of domain 1. Domain 2 is homologous to epidermal growth factor (EGF) precursor, suggesting a possible evolutionary or functional relationship. [Reproduced with permission from M. S. Brown and J. L. Goldstein, A receptor-mediated pathway for cholesterol homeostasis. Science 232, 34 (1986).]...

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