title: Complexity of sea urchin embryo nuclear proteins that contain basic domains.
abstract: We describe a quantitative two-dimensional gel electrophoretic analysis of nuclear extract from 24-hr sea urchin embryos. The extract was fractionated by using a weak cation-exchange resin, and eight known DNA-binding proteins were shown to be entirely included in a salt eluate that releases proteins containing basic domains. This fraction and a lower-salt fraction containing the majority of the protein species were mapped two-dimensionally by using new algorithms that permit reproducible spot identification, storage of intensity and map-position data, and subtractive comparison of one pattern with respect to another. By reference to a previously characterized DNA-binding factor, spot intensity could be interpreted in terms of the number of molecules per embryo nucleus. A map was constructed displaying all nuclear proteins containing basic domains that are present within the concentration range per nucleus of a set of known DNA-binding factors of the sea urchin embryo. The map includes 265 spots that fulfill both of these criteria, probably representing about 100 different protein species.
authors.affiliation: Division of Biology, California Institute of Technology, Pasadena 91125.
authors.forename: M G
authors.initials: MG
authors.lastname: Harrington
authors.forename: J A
authors.initials: JA
authors.lastname: Coffman
authors.forename: F J
authors.initials: FJ
authors.lastname: Calzone
authors.forename: L E
authors.initials: LE
authors.lastname: Hood
authors.forename: R J
authors.initials: RJ
authors.lastname: Britten
authors.forename: E H
authors.initials: EH
authors.lastname: Davidson
mesh_terms: D000818:Animals; D002852:Chromatography, Ion Exchange; D004268:DNA-Binding Proteins / Q000737:chemistry*; D015180:Electrophoresis, Gel, Two-Dimensional; D007526:Isoelectric Point; D009687:Nuclear Proteins / Q000737:chemistry*; D012617:Sea Urchins / Q000737:chemistry / Q000196:embryology*
chemical_list: D004268:DNA-Binding Proteins; D009687:Nuclear Proteins