Nirmala P B, Thampan R V
Department of Biochemistry, School of Life Sciences, University of Hyderabad, India.
Arch Biochem Biophys. 1995 Jun 1;319(2):551-61. doi: 10.1006/abbi.1995.1330.
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.
从山羊子宫胞质溶胶中纯化出的一种55千道尔顿的蛋白质（p55）可将雌激素受体（ER）转运至细胞核。使用含有高浓度赖氨酸的缓冲液从雌激素受体 - 琼脂糖柱上选择性洗脱该蛋白质，以及它与聚-L-赖氨酸 - 琼脂糖的高亲和力，表明它能识别雌激素受体中富含赖氨酸的区域。它与微管蛋白 - 琼脂糖和肌动蛋白 - 琼脂糖的强结合表明细胞骨架成分在由p55介导的雌激素受体核转运中发挥作用。该蛋白质可在子宫胞质溶胶在肌动蛋白 - 琼脂糖柱上进行层析后一步纯化。针对聚-L-天冬氨酸产生的抗体与p55发生交叉反应，并抑制了雌激素受体的核转运。p55与SV40大T抗原的异源核定位序列的结合表明它可能还参与了除雌激素受体之外的其他蛋白质的转运。
