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- **********************************************
- * EGF-like domain cysteine pattern signature *
- **********************************************
-
- A sequence of about thirty to forty amino-acid residues long found in the
- sequence of epidermal growth factor (EGF) has been shown [1,2,3,4,5] to be
- present, in a more or less conserved form, in a large number of other
- proteins. The proteins currently known to contain one or more copies of an
- EGF-like pattern are listed below (references are only provided for very
- recently sequenced proteins).
-
- - Transforming growth factor alpha (TGF-alpha).
- - Amphiregulin, a growth factor.
- - Schwannoma-derived growth factor (SDGF).
- - Betacellulin, a growth factor [6].
- - Growth factor related proteins from Vaccinia, Myxoma, and Shope fibroma
- viruses.
- - Coagulation factors VII, IX, X (once) and XII (twice).
- - Coagulation associated proteins C, S and Z (once).
- - Urokinase and tissue plasminogen activator (TPA) (once).
- - Complement components C6, C7, C8 alpha and beta chains, and C9 (once).
- - Fibronectin (twice).
- - Laminin subunits A (15 times), B1 (13 times) and B2 (12 times).
- - Tenascin, an extracellular matrix protein (14 times).
- - Nidogen (also called entactin), a basement membrane protein (once).
- - Agrin, a basal lamina protein that causes the aggregation of acetylcholine
- receptors on cultured muscle fibers (4 times).
- - Aggrecan (once) and versican (twice), two large proteoglycans.
- - Selectins, cell adhesion proteins such as ELAM-1 (E-selectin), GMP-140
- (P-selectin), or the lymph-node homing receptor (L-selectin) (once).
- - Transforming growth factor beta-1 binding protein (TGF-B1-BP) (16 times).
- - Drosophila neurogenic proteins: Notch (36 times), Delta (9 times), and Slit
- (7 times).
- - Drosophila epithelial development protein Crumbs (30 times).
- - Drosophila ectodermal development protein Serrate (14 times).
- - Caenorhabditis elegans developmental proteins lin-12 (13 times) and glp-1
- (10 times).
- - Sea urchin protein uEGF-1 (at least 9 times).
- - Human teratocarcinoma-derived growth factor 1 (TDGF-1) (CRIPTO protein)
- (once).
- - Milk fat globule-EGF factor 8 (MFG-E8) (twice).
- - Tyrosine-protein kinase receptors tek and tie (3 times) [7].
-
- The functional significance of EGF domains in what appear to be unrelated
- proteins is not yet clear. However, a common feature is that these repeats are
- found in the extracellular domain of membrane-bound proteins or in proteins
- known to be secreted. The EGF domain includes six cysteine residues which have
- been shown (in EGF) to be involved in disulfide bonds. The schematic
- representation of the EGF-like type A domain is shown here:
-
- +-----------+ +--------+
- | | | |
- xxxCxxxxCxxxxxCxxxxxCxCxxxxxxxxCxxx
- | | ************
- +----------+
-
- 'C': conserved cysteine involved in a disulfide bond.
- '*': position of the pattern.
-
- We have used the region which includes the last three cysteines of the domain
- as a consensus pattern.
-
- -Consensus pattern: C-x-C-x(5)-G-x(2)-C
- [The three C's are involved in disulfide bonds]
- -Sequences known to belong to this class detected by the pattern: ALL.
- -Other sequence(s) detected in SWISS-PROT: 38 other proteins. It is also found
- twice in the beta chain of the integrin family of proteins. The presence of
- cysteine-rich repeat patterns in these proteins had already been noted but
- they were said to be dissimilar with the EGF pattern [8].
-
- -Note: the residue in position -2 to the glycine is very often an aromatic (F,
- Y or W) residue.
- -Note: this pattern does not detect some of the repeats of laminins A, B1 and
- B2, Crumbs, Notch, TGF-B1-BP, and lin-12.
-
- -Last update: June 1994 / Text revised.
-
- [ 1] Davis C.G.
- New Biol. 2:410-419(1990).
- [ 2] Blomquist M.C., Hunt L.T., Barker W.C.
- Proc. Natl. Acad. Sci. U.S.A. 81:7363-7367(1984).
- [ 3] Barker W.C., Johnson G.C., Hunt L.T., George D.G.
- Protein Nucl. Acid Enz. 29:54-68(1986).
- [ 4] Doolittle R.F., Feng D.F., Johnson M.S.
- Nature 307:558-560(1984).
- [ 5] Appella E., Weber I.T., Blasi F.
- FEBS Lett. 231:1-4(1988).
- [ 6] Shing Y.W., Christofori G., Hanahan D., Ono Y., Sasada R., Igarashi K.,
- Folkman J.
- Science 259:1604-1607(1993).
- [ 7] Ziegler S.F., Bird T.A., Schneringer J.A., Schooley K.A., Baum P.R.
- Oncogene 8:663-670(1993).
- [ 8] Tamkun J.W., DeSimone D.W., Fonda D., Patel R.S., Buck C., Horwitz A.F.,
- Hynes R.O.
- Cell 46:271-282(1986).
-