title: Epithelins 1 and 2: isolation and characterization of two cysteine-rich growth-modulating proteins.
abstract: Two proteins, termed epithelin 1 and epithelin 2, that inhibit the growth of A431 cells, derived from a human epidermal carcinoma of the vulva, have been purified from rat kidney. Epithelin 1 stimulates the proliferation of murine keratinocytes, whereas epithelin 2 inhibits the epithelin 1-elicited growth of these cells. Thus epithelin 1 and 2 behave as agonist and antagonist, respectively, for normal epithelial cells. Epithelins are low molecular mass (approximately 6 kDa), acid- and heat-stable, single-chain proteins containing approximately 20% cysteine. Some of these cysteines form disulfide linkage(s) that are essential for biological activity. The amino-terminal amino acid sequences of epithelin 1 and epithelin 2 have been determined. The two proteins showed no substantial sequence homology with other proteins. However, a significant homology was seen between the amino-terminal sequences of epithelin 1 and epithelin 2. Epithelins 1 and 2, therefore, appear to represent members of a distinct family of growth regulators.
authors.affiliation: Oncogen, Seattle, WA 98121.
authors.forename: M
authors.initials: M
authors.lastname: Shoyab
authors.forename: V L
authors.initials: VL
authors.lastname: McDonald
authors.forename: C
authors.initials: C
authors.lastname: Byles
authors.forename: G J
authors.initials: GJ
authors.lastname: Todaro
authors.forename: G D
authors.initials: GD
authors.lastname: Plowman
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D002460:Cell Line; D002850:Chromatography, Gel; D002851:Chromatography, High Pressure Liquid; D003545:Cysteine; D004261:DNA Replication / Q000187:drug effects*; D000077155:Granulins; D006131:Growth Inhibitors / Q000302:isolation & purification* / Q000494:pharmacology; D006133:Growth Substances / Q000302:isolation & purification* / Q000494:pharmacology; D006801:Humans; D036341:Intercellular Signaling Peptides and Proteins; D015603:Keratinocytes / Q000166:cytology* / Q000187:drug effects; D007668:Kidney / Q000737:chemistry / Q000502:physiology*; D007700:Kinetics; D051379:Mice; D008815:Mice, Inbred Strains; D008969:Molecular Sequence Data; D051381:Rats
chemical_list: D000077155:Granulins; D006131:Growth Inhibitors; D006133:Growth Substances; D036341:Intercellular Signaling Peptides and Proteins; D003545:Cysteine