Wennborg A, Sohlberg B, Angerer D, Klein G, von Gabain A
Microbiology and Tumorbiology Center, Karolinska Institute, Stockholm, Sweden.
Proc Natl Acad Sci U S A. 1995 Aug 1;92(16):7322-6. doi: 10.1073/pnas.92.16.7322.
We have detected an endoribonucleolytic activity in human cell extracts that processes the Escherichia coli 9S RNA and outer membrane protein A (ompA) mRNA with the same specificity as RNase E from E. coli. The human enzyme was partially purified by ion-exchange chromatography, and the active fractions contained a protein that was detected with antibodies shown to recognize E. coli RNase E. RNA containing four repeats of the destabilizing motif AUUUA and RNA from the 3' untranslated region of human c-myc mRNA were also found to be cleaved by E. coli RNase E and its human counterpart in a fashion that may suggest a role of this activity in mammalian mRNA decay. It was also found that RNA containing more than one AUUUA motif was cleaved more efficiently than RNA with only one or a mutated motif. This finding of a eukaryotic endoribonucleolytic activity corresponding to RNase E indicates an evolutionary conservation of the components of mRNA degradation systems.
我们在人细胞提取物中检测到一种核糖核酸内切酶活性，该活性对大肠杆菌9S RNA和外膜蛋白A（ompA）mRNA的加工具有与大肠杆菌RNase E相同的特异性。通过离子交换色谱法对人源酶进行了部分纯化，活性组分中含有一种蛋白质，用能识别大肠杆菌RNase E的抗体可检测到该蛋白质。含有四个不稳定基序AUUUA重复序列的RNA以及人c-myc mRNA 3'非翻译区的RNA也被大肠杆菌RNase E及其人源对应物切割，这种切割方式可能表明该活性在哺乳动物mRNA降解中发挥作用。还发现含有多个AUUUA基序的RNA比仅含有一个或突变基序的RNA切割效率更高。这种与RNase E相对应的真核核糖核酸内切酶活性的发现表明mRNA降解系统的组成成分在进化上具有保守性。
