The nuclease that selectively degrades albumin mRNA in vitro associates with Xenopus liver polysomes through the 80S ribosome complex.
The nuclease that selectively degrades albumin mRNA in vitro associates with Xenopus liver polysomes through the 80S ribosome complex.
复制标题
体外选择性降解白蛋白 mRNA 的核酸酶通过 80S 核糖体复合物与非洲爪蟾肝多核糖体结合。
DOI：
10.1006/abbi.1993.1428
复制
发表时间：
1993
影响因子：
3.9
通讯作者：
Schoenberg,DR
中科院分区：
文献类型：
--
作者：
Pastori,RL;Schoenberg,DR
先前在xenopusliver多聚体上发现了一种核糖核酸酶的活性，这种酶具有预期的特征，可以催化雌激素给药后血清蛋白编码mrna的调节不稳定。这种酶的活性是雌激素诱导的，并选择性地降解mrna（例如，白蛋白，γ-纤维蛋白原），这些mrna在雄性青蛙服用雌激素后不稳定。本文报道了该酶的活性与40S和60S核糖体亚基的关联关系。核糖核酸酶活性（由白蛋白RNA产生的特定裂解片段定义）存在于含有大部分肝脏mRNA的多聚体中。这种活性沉淀在蔗糖梯度上，在卵黄动物的肝脏中观察到大的多体复合物。EDTA处理产生40S和60S核糖体亚基以及大量的80S核糖体单体。在这些条件下，多体核糖核酸酶在溶液和80S材料中都是游离的。嘌呤霉素治疗主要产生40S和60S核糖体亚基。多体核糖核酸酶活性仅在嘌呤霉素治疗后的溶液中发现。这些数据表明，xenopusliver多体核酸酶需要两种核糖体亚基结合才能与多体形成复合物。多体核酸酶在Mono Q层析上表现为碱性蛋白，分离的物质对白蛋白和铁蛋白mRNA保持相同的差异活性。
A ribonuclease activity that has characteristics expected for an enzyme that catalyzes the regulated destabilization of serum protein-coding mRNAs following estrogen administration was previously identified onXenopusliver polysomes. This enzyme activity is estrogen inducible and selectively degrades mRNAs (e.g., albumin, γ-fibrinogen) that are unstable following estrogen administration to male frogs. This paper reports on the relationship between this enzyme activity and the association of 40S and 60S ribosomal subunits. Ribonuclease activity (as defined by the generation of a specific cleavage fragment from albumin RNA) is found in polysome fractions that contain the majority of the liver mRNA. This activity sediments on sucrose gradients with the large polysome complexes observed in liver of vitellogenic animals. EDTA treatment generates 40S and 60S ribosome subunits and a significant amount of 80S ribosome monomers. Under these conditions, polysomal ribonuclease activity is found both free in solution and with the 80S material. Puromycin treatment generates predominantly 40S and 60S ribosomal subunits. Polysomal ribonuclease activity is found only in solution following puromycin treatment. These data indicate that theXenopusliver polysomal nuclease requires the association of both ribosomal subunits for complex formation with polysomes. The polysomal nuclease behaves as a basic protein on Mono Q chromatography, with the fractionated material retaining the same differential activity toward albumin versus ferritin mRNA.