Association of androgen binding sites with the endoplasmic reticulum of rat ventral prostate.
Association of androgen binding sites with the endoplasmic reticulum of rat ventral prostate.
复制标题
雄激素结合位点与大鼠腹侧前列腺内质网的关联。
DOI：
10.1095/biolreprod42.2.337
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发表时间：
1990
影响因子：
3.6
通讯作者：
Muldoon,TG
中科院分区：
文献类型：
--
作者：
Steinsapir,J;EvansJr,AC;McDonald,T;Muldoon,TG
24小时去势大鼠前列腺腹侧的微生物体包含一组组织特异性的高亲和力、低容量的雄激素结合位点。通过与标记酶相关的纯化程序和电子显微镜分析表明，这些位置是内质网固有的。当用核或线粒体颗粒作为蔗糖梯度分级的来源时，前列腺微体膜与质膜分离时，雄激素结合活性选择性地与富含粗面内质网和核糖体的部分相关联。当核悬浮液作为膜来源时，84%的Na+/K+腺苷三磷酸酶(ATPase)总含量和总结合量只有27%集中在表面光滑的囊泡膜中。相反，当粗面内质网丰富而质膜含量不足时，相同梯度的区域含有73%的雄激素结合力，而只有14%的ATPase。以线粒体悬浮液为起始原料收集的组分，其总葡萄糖-6-磷酸酶/总结合量的比值比类似的ATPase/结合量的比值更接近1.0，表明结合部位与微粒体膜而不是与质膜共沉淀。Na+/K+ATPase是一种有效的前列腺腹侧质膜标记物，而5‘核苷酸酶不是。微粒体雄激素受体可能在靶细胞中构成雄激素作用的一个新的调节水平。
Microsomes from ventral prostate of 24-h castrated rats contain a single set of tissue-specific high-affinity, low-capacity androgen binding sites. These sites are indigenous to the endoplasmic reticulum, as shown by purification procedures associated with marker enzymes and electron microscopic analyses. When prostatic microsomal membranes are separated from plasma membranes using the nuclear or the mitochondrial pellets as the source of fractionation in sucrose gradients, the androgen binding activity is selectively associated with fractions rich in rough endoplasmic reticulum and ribosomes. Eighty-four percent of the total content of Na+/K+adenosine triphosphatase (ATPase) and only 27% of the total binding capacity were concentrated in fractions rich in smooth-surfaced vesicular membranes, when nuclear suspensions constituted the membrane source. In contrast, the region of the same gradient when enriched in rough endoplasmic reticulum and deficient in plasma membrane content contained 73% of the androgen-binding capacity and only 14% of the ATPase. For fractions collected using mitochondrial suspensions as starting material, the ratio (total glucose-6-phosphatase/total binding capacity) was closer to 1.0 than similar ratios of ATPase/binding capacity, indicating co-sedimentation of binding sites with microsomal membranes and not with plasma membranes. Na+/K+ATPase, but not 5′ nucleotidase, is a valid plasma membrane marker for ventral prostate. Microsomal androgen receptors may constitute a new level of regulation of androgen action in target cells.