Murayama A, Fukai F, Yamamoto T
J Biochem. 1980 Nov;88(5):1457-66. doi: 10.1093/oxfordjournals.jbchem.a133115.
Analysis of estrogen receptor-binding factors (ERBFs) under isotonic (0.15 M KCl) conditions showed the presence of a factor designated as "7S" estrogen receptor-forming factor [("7S" ER)-FF], which binds with native "4S" estrogen receptor (ER) to form "7S" ER, besides the previously described component B and its hexamer ["6S" ER-forming factor, ("6S" ER)-FF]. Under hypertonic (0.4 M KCl) conditions at lower temperature (4 degrees C), ("7S" ER)-FF and the monomer of component B were present. Under hypertonic conditions at higher temperature (25 degrees C), ERBF existed as component A ["5S" ER-forming factor, ("5S" ER)-FF] and component B. ("7S" ER)-FF was estimated to be a 1 : 2 complex of component A and component B. Under isotonic conditions, approximately 30% of the cytoplasmic ER was "4S" form, and the rest was "6S" and "7S" forms. "5S" ER, "6S" ER, "7S" ER, and "8S" ER were reconstituted from partially purified native "4S" ER and the corresponding ERBFs. "5S" ER was estimated to be a 1 : 1 complex of native "4S" ER and ("5S" ER)-FF. "6S" ER was estimated to be a 1 : 1 complex of native "4S" ER and ("6S" ER)-FF. "7S" ER was estimated to be a 1 : 1 complex of native "4S" ER and ("7S" ER)-FF. "8S" ER was estimated to be a 1 : 1 complex of native "4S" ER and the "8S" ER-forming factor [("8S" ER)-FF] previously described, in which component A is bound to "4S" ER not directly, but via component B. A schematic molecular model of the in vitro dissociation and assembly of the constituents of the cytoplasmic ER system of cow uterus is presented.
在等渗（0.15M KCl）条件下对雌激素受体结合因子（ERBFs）的分析表明，除了先前描述的组分B及其六聚体["6S"雌激素受体形成因子，("6S" ER)-FF]外，还存在一种被命名为“7S”雌激素受体形成因子[("7S" ER)-FF]的因子，它与天然的“4S”雌激素受体（ER）结合形成“7S” ER。在低温（4℃）的高渗（0.4M KCl）条件下，存在("7S" ER)-FF和组分B的单体。在高温（25℃）的高渗条件下，ERBF以组分A["5S"雌激素受体形成因子，("5S" ER)-FF]和组分B的形式存在。("7S" ER)-FF估计是组分A和组分B的1:2复合物。在等渗条件下，大约30%的细胞质ER是“4S”形式，其余是“6S”和“7S”形式。“5S” ER、“6S” ER、“7S” ER和“8S” ER由部分纯化的天然“4S” ER和相应的ERBFs重构而成。“5S” ER估计是天然“4S” ER与("5S" ER)-FF的1:1复合物。“6S” ER估计是天然“4S” ER与("6S" ER)-FF的1:1复合物。“7S” ER估计是天然“4S” ER与("7S" ER)-FF的1:1复合物。“8S” ER估计是天然“4S” ER与先前描述的“8S”雌激素受体形成因子[("8S" ER)-FF]的1:1复合物，其中组分A不是直接与“4S” ER结合，而是通过组分B结合。本文给出了奶牛子宫细胞质ER系统成分体外解离和组装的示意性分子模型。
