Clerch L B, Wright A, Chung D J
Georgetown University School of Medicine, Lung Biology Laboratory, Washington, DC 20007, USA.
Biochem Biophys Res Commun. 1996 May 15;222(2):590-4. doi: 10.1006/bbrc.1996.0788.
Rat lung extract contains protein that binds to a cis element in the 3' untranslated region of glutathione peroxidase (GPx) mRNA; this region is located 200 bases downstream of the stop codon and 77 bases downstream of the selenocysteine insertion sequence. GPx mRNA-binding protein (GPx-BP) has the following characteristics in common with Mn superoxide dismutase mRNA-binding protein (MnSOD-BP): 1. RNA-binding activity is redox-sensitive; free sulfhydryl groups on the protein are required for binding. 2. RNA-binding activity is enriched in a 130,000 x g supernatant fraction and is inhibited by RNA in the polysomal fraction. 3. The MnSOD and GPx cis elements compete with each other for protein binding. 4. UV crosslinking studies with each probe reveal a [32P]-labeled protein of the same apparent molecular mass, 56 kDa. These observations provide evidence that MnSOD and GPx RNAs bind the same protein.
大鼠肺提取物含有一种蛋白质，它能与谷胱甘肽过氧化物酶（GPx）mRNA 3'非翻译区的一个顺式元件结合；该区域位于终止密码子下游200个碱基处，硒代半胱氨酸插入序列下游77个碱基处。GPx mRNA结合蛋白（GPx-BP）与锰超氧化物歧化酶mRNA结合蛋白（MnSOD-BP）具有以下共同特征：1. RNA结合活性对氧化还原敏感；蛋白质上的游离巯基是结合所必需的。2. RNA结合活性在130,000×g上清液组分中富集，并受到多核糖体组分中RNA的抑制。3. MnSOD和GPx顺式元件相互竞争蛋白质结合。4. 用每种探针进行的紫外线交联研究揭示了一种表观分子量相同的[32P]标记蛋白质，即56 kDa。这些观察结果提供了证据，表明MnSOD和GPx RNA结合相同的蛋白质。
