title: A 55-kDa protein (p55) of the goat uterus mediates nuclear transport of the estrogen receptor. I. Purification and characterization.
abstract: A 55-kDa protein (p55), purified from the goat uterine cytosol, transports estrogen receptor (ER) into the nucleus. Selective elution of this protein from a column of estrogen receptor-Sepharose using buffers containing high concentrations of lysine and the high affinity with which it binds to poly-L-lysine-Sepharose indicate that it recognizes a lysine-rich region in the ER. Its strong binding to tubulin-Sepharose and actin-Sepharose is indicative of a role that the cytoskeletal elements play in the nuclear transport of the ER, mediated by p55. This protein can be purified in a single step following chromatography of the uterine cytosol on a column of actin-Sepharose. Antibodies raised against poly-L-aspartic acid cross-reacted with p55 and inhibited the nuclear transport of the ER. The binding of p55 to a heterologous nuclear localization sequence of the SV40 large T suggests that it may also be involved in the transport of proteins other than the ER.
authors.affiliation: Department of Biochemistry, School of Life Sciences, University of Hyderabad, India.
authors.forename: P B
authors.initials: PB
authors.lastname: Nirmala
authors.forename: R V
authors.initials: RV
authors.lastname: Thampan
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001224:Aspartic Acid / Q000737:chemistry / Q000378:metabolism; D001692:Biological Transport / Q000187:drug effects; D002352:Carrier Proteins / Q000302:isolation & purification* / Q000494:pharmacology; D002467:Cell Nucleus / Q000378:metabolism*; D005260:Female; D006041:Goats; D008969:Molecular Sequence Data; D009687:Nuclear Proteins / Q000302:isolation & purification* / Q000494:pharmacology; D011960:Receptors, Estrogen / Q000187:drug effects / Q000378:metabolism*; D014599:Uterus / Q000737:chemistry / Q000378:metabolism*
chemical_list: D002352:Carrier Proteins; D009687:Nuclear Proteins; D011960:Receptors, Estrogen; D001224:Aspartic Acid