Identification and localization of deoxyribonuclease I in the rat ovary
Identification and localization of deoxyribonuclease I in the rat ovary
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DOI：
10.1095/biolreprod57.4.813
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发表时间：
1997-10-01
影响因子：
3.6
通讯作者：
Tsang, BK
中科院分区：
文献类型：
--
作者：
Boone, DL;Tsang, BK
我们的目的是鉴定卵巢中负责DNA降解的内切酶，并确定其相对于卵巢卵泡发育状态的定位。未成熟大鼠分别给予己烯雌酚（DES组）、DES + eCG （eCG组）或DES + eCG + hCG （hCG组）治疗。除DES组外，eCG和hCG组细胞核中含有32/34 kda DNase I样内切酶活性，该酶依赖于Ca2+/Mg2+，受Mn2+刺激，pH为7时最佳，并经抗DNase I抗体鉴定。g -肌动蛋白、Zn2+、二硫苏糖醇、金三羧酸和金硫硫酸钠抑制活性，但碘乙酸不抑制活性。将心电核蛋白提取物添加到DES组的细胞核中可诱导寡核体DNA断裂，用抗dnase I抗体预处理提取物可防止这种断裂。dna酶I免疫定位于健康黄体细胞、卵泡颗粒细胞、卵泡前卵母细胞、闭锁卵泡前卵母细胞和睾丸精原细胞的细胞核中，但未在卵泡前颗粒细胞、卵泡细胞、卵泡前卵母细胞或睾丸精母细胞中观察到。大鼠肾、肝、脾、牛、鸡和人卵巢的核提取物显示出DNase - 1样活性。这些结果表明，一种与DNA酶I难以区分的内切酶负责卵巢细胞凋亡的DNA降解。
Our objective was to identify the endonuclease responsible for DNA degradation in the ovary and determine its localization relative to the developmental state of ovarian follicles. Immature rats were treated with diethylstilbestrol (DES; DES group), DES + eCG (eCG group) or DES + eCG + hCG (hCG group). Nuclei of the eCG and hCG but not the DES group contained a 32/34-kDa DNase I-like endonuclease activity that was Ca2+/Mg2+-dependent, stimulated by Mn2+ optimal at pH 7, and identified by anti-DNase I antibody. G-actin, Zn2+, dithiothreitol, aurintricarboxylic acid, and sodium aurothiomalate, but not iodoacetic acid, inhibited the activity. Addition of eCG nuclear protein extracts to nuclei from the DES group induced oligonucleosomal DNA fragmentation, which could be prevented by pretreatment of the extracts with anti-DNase I antibody. DNase I was immunolocalized in nuclei of healthy luteal cells, antral follicle granulosa cells, oocytes of preantral follicles, atretic preantral follicles, and testicular spermatogonia, but was not observed in granulosa cells of preantral follicles, theca cells, antral follicle oocytes, or testicular spermatocytes. Nuclear extracts of rat kidney, liver, and spleen, and bovine, chicken, and human ovaries displayed DNase I-like activity. These results suggest that an endonuclease indistinguishable from DNase I is responsible for ovarian apoptotic DNA degradation.