Ghosh A, Ghosh T, Ghosh S, Das S, Adhya S
Genetic Engineering Laboratory, Indian Institute of Chemical Biology, Calcutta.
Nucleic Acids Res. 1994 May 11;22(9):1663-9. doi: 10.1093/nar/22.9.1663.
Using synthetic antisense RNA from the 5'-untranslated region of the beta-tubulin gene as probe in gel retardation assays, a heat stable RNA-binding factor was identified in promastigotes of the kinetoplastid protozoan Leishmania donovani. The same or similar factors interact with several small ribosomal RNA (srRNA) species and, more weakly, with tRNA, as shown by binding and competition experiments. Deletion analysis indicated involvement of repeated purine-rich motifs on the antisense RNA, in the reaction. Related, conserved motifs occur on at least two of the srRNAs. By a modified Western blot assay, the RNA-binding species was identified as a single, small polypeptide. The activity is apparently specific for the promastigote stage of the parasite, being undetectable in amastigotes. The properties of this RNA-binding factor suggest that it is a novel, previously uncharacterized protein.
在凝胶阻滞分析中，使用来自β-微管蛋白基因5'-非翻译区的合成反义RNA作为探针，在动质体原生动物杜氏利什曼原虫的前鞭毛体中鉴定出一种热稳定的RNA结合因子。结合和竞争实验表明，相同或相似的因子与几种小核糖体RNA（srRNA）相互作用，与tRNA的相互作用较弱。缺失分析表明反义RNA上富含嘌呤的重复基序参与了该反应。相关的保守基序至少出现在两种srRNA上。通过改良的蛋白质印迹分析，RNA结合物质被鉴定为一种单一的小多肽。该活性显然对寄生虫的前鞭毛体阶段具有特异性，在无鞭毛体中无法检测到。这种RNA结合因子的特性表明它是一种新型的、以前未被表征的蛋白质。
